There's an inverse relationship between the prevalence of a given technology and its unit cost; the more of it that's made, the more is learned about how to produce it cheaply and efficiently, which means that the retail price can be reduced without lowering the manufacturer's profits. Newly developed technologies haven't existed for long enough to let this relationship take effect, so they tend to be very costly to purchase and maintain.

Stories often use this as a reason not to just blow up rampaging technology, or to make an item more important [[MacGuffin as a setup to get it destroyed or rescued]]. This approach also allows some characters or factions to have some items better than others without making plot holes or contrived limitations like [[SuperPrototype Super Prototypes]]. It helps explain why stories don't simply have a whole lot of certain tech items -- e.g. why are there only a few flying suits assigned to an elite team or even just its lead members, instead of jetpacks being issued to every private in the army? Because they cost too much. Which art-wise makes a justification for the greater variety of used designs. And if the author ever decides to change designs, raise the stakes or avoid going too far with TheWorfEffect or RedshirtArmy, the mass upgrade "at last" improves the {{continuity}} instead of taxing it.

Here's a partial list of potential expenses:
* Efforts toward further development and refinement
* High engineering requirements (reducing the number of facilities which can produce a given item at all; increasing the rate of production rejects, which reduces the number of items which can be put on the market)
* High material requirements (raw materials which are rare or expensive to obtain; complex and time-consuming material refinement processes)
* Unusual power source (rare fuels, radioisotopes, AppliedPhlebotinum)

As this is extremely common, please limit examples to subversions, aversions, taken {{Up To Eleven}}, or if it becomes a major plot point.

[[AC:{{Anime}} and {{Manga}}]]
* Astronomical amounts of money [[KaijuDefenceForce JSDF]] has sunk into the military {{cyborg}}s research and development during the WWIV shortly prior to Anime/GhostInTheShellArise, is one of the main reasons it is in such a [[PerpetualPoverty dire financial straits]] in the show.
* Many one-shot or limited production suits from the various ''Anime/MobileSuitGundam'' series are prototypes that were just too expensive or complex to mass produce. In fact, most series star a unique SuperPrototype. Others were created for [[AllThereInTheManual Mobile Suit Variations]] series to demonstrate how technology advanced behind the scenes.
** The original Gundam anime makes this a plot point with the introduction of the mass produced [=GMs=]. While vastly weaker to the Gundam, the Federation reasons that being able to produce entire armies of [=GMs=] to take advantage of their huge pilot pool is more likely to win the war than producing a small handful of obscenely expensive Gundams.
** This also comes up later after the introduction of the Zeon Gelgoog, which is described as being roughly equal to (if not superior to) the Gundam itself. Technology had progressed to the point where it was now cost-effective to mass produce Mobile Suits on par to the Gundam.

* In some canons, one of ''{{Spider-Man}}'''s major plot is budget on the expensive chemicals for his web shooters.

* In ''[[{{Spider-Man}} Spider-Man 2]]'', when Doctor Octopus' tentacles convince him to try to build his fusion generator again, he specifically mentions needing to be able to fund it, which results in him robbing the bank where he has his first fight with Spider-Man.
* WesternAnimation/DespicableMe: A huge part of the plot involved getting loans and necessary capitol in order to create the evil inventions for the evil plots. They had their own Villain Bank.
* In ''Film/{{Contact}}'', a terrorist attack destroys the first device. There are plans, but building the device was so expensive for the entire world that the prospect of building a second one (especially since it would invite yet another attack) is summarily dismissed. It is then that a second, backup device is revealed to have been built in secret. It is explained with the CrowningMomentOfAwesome line:
-->"First rule of government spending: why build one, when you can build two, at twice the price? Only, this one can be kept secret.

* In ''[[Literature/EinsteinsBridge Einstein's Bridge]]'', the expense of SSC were used as one of reasons to close that project.
* Part of the issues in the war between the People's Republic of Haven and Manticore in the ''Literature/HonorHarrington'' series. Courtesy of their control of the largest known wormhole junction in the Galaxy and a massive merchant marine Manticore can afford to run a robust R&D program in the middle of a shooting war while the bankrupt PRH can't, even if their educational system wasn't hideously crippled.
* Justifies the SchizoTech in the ''Literature/BelisariusSeries'': both opposing forces have men armed with everything from [[BladeOnaStick spears]] to [[GatlingGood volley guns]], due to the expense of trying to fight an industrial war using a preindustrial society.

* In one of DoctorSteel's songs, "Build the Robots", Dr. Steel laments about building a high-tech giant robot army:
--> I need assembly lines
--> A crew and much more time.
--> The money's all mine
--> And my funds are getting thin.
--> I'm gonna have to rob a bank again.
--> 'Cause I'm spending every dime and
--> I'm spending all my time to
--> Build the robots.

* ''GeniusTheTransgression'' goes a little overboard in insisting that Geniuses be able to account for ''how'', exactly, they pay for those wonderful toys. It stops short of having the Storyteller request an itemized budget from the players, but only just.
* ''TabletopGame/D20Modern'' provides rules in the ''d20 Future'' sourcebook for buying advanced gear as well as modern gear made more advanced by heavy modification, with set increases in the cost for each boost. Yes, you can have yourself a SniperPistol if you're willing to shell out.

* Strategy games sometimes have "miniaturization" effects - an eventual reduction in cost of hardware that isn't new as the player climbs higher on TechTree in corresponding fields, which leaves it a viable choice for some time.
* ''Stars!'' makes each item cheaper by 4% per TechLevel prerequisite (if it has any) exceeded in all applicable fields, until its resource cost drops to 24%. "[[ Bleeding Edge Technology]]" trait, doubles the cost of new technologies until Tech Levels are exceeded, but improves by 5%/level with 20% bottom. This sucks on highest-level items, however, since there's no room left for improvement and you're just stuck with double cost until the end.
* In ''VideoGame/MasterOfOrion 2'' "[[ miniaturization]]" lowers both the cost and size of devices, and empty levels at the top of the TechTree exist to allow extra miniaturization of top-tier tech (and score points).
* ''SidMeiersAlphaCentauri'' has prototyping, where the first unit of a new design has an added initial cost before you can even produce any. This cost is ignored by the Spartans and at bases with a Skunkworks.
** Prototypes have a special advantage, as well: because prototypes are typically entrusted to experienced personnel, these units gain a boost to Morale (i.e. XP). Significantly, this still applies when the prototype is built at the Skunkworks...but ''not'' for the Spartans. Not that they need the boost (they start at +2 Morale, so giving them the extra boost would just be overkill).
* ''SwordOfTheStars II'' also introduces prototyping. You can't start mass-producing new ship designs until you build the prototype. Prototypes are subject to the RandomNumberGod. Certain qualities (firepower, armor, energy production, etc.) can be slightly better or worse than the mass-produced sister ships, which is why the designers saw fit to give prototypes nicknames reflecting their qualities.
* In the ''Franchise/{{Halo}}'' universe, the [[FrickinLaserBeams Spartan Laser]] costs as much as A 400,000 TON WARSHIP.
* In ''VideoGame/MassEffect1'', it is observed that for what the Systems Alliance spent on the ''[[CoolStarship Normandy SR-1]]'', they could have built and outfitted an entire flotilla of standard frigates. The ''Normandy'' is of course a SuperPrototype with unmatched stealth capabilities. In ''VideoGame/MassEffect2'', the ''Normandy SR-2'' is indicated to be even more expensive and capable than her predecessor.
** The [[WeCanRebuildHim Lazarus Project]] brings Shepard back from being frozen and brain-dead, but is so incomprehensibly expensive that even [[NGOSuperpower Cerberus]] can't do it again.
** The [[WaveMotionGun Thanix cannon]] is another solid example. Developed between the first and second games from the reverse-engineered wreckage of Sovereign, in ''Mass Effect 2'' you can obtain ''one'' prototype cannon fitting for your frigate, and that only because of your high-level contacts with the turian government -- and they [[DoubleUnlock still make you build parts yourself]]. By the endgame of ''Mass Effect 3'', they're bloody everywhere; Cerberus has them mounted on Omega, the Alliance and turians field entire fleets equipped with them, and the volus built ''[[MileLongShip a dreadnought]]'' with Thanix technology.
* ''VideoGame/{{Civilization}} IV'' uses this as part of their approach to the series' traditional TechTree. While you don't have to research all of the prerequisites for certain technologies, doing so reduces the research costs.
** Inverted in ''Civilization V: Brave New World'' with the "Scholars in Residence" [[FictionalUnitedNations UN edict]], which makes technologies cheaper for other civs after the first one researches it. Old Tech ''Is'' Cheap.
* ''VideoGame/StarcraftII'':
** This trope is invoked as to why Raynor does not only artifact misions but any other mission he can find, including for notorious pirates.
** The Odin, the Dominion's ultimate assault mech, is capable of ravaging multiple bases with barely any maintenance, but is so expensive and outright huge (even the biggest cargo ship in the game can't fit it) there's only one ever built in the entire series. Fortunately, Swann reverse engineers it and comes up with a mass-production version which cuts back certain elements like the size, the minibar and toilet in the cockpit, and the nuclear missile launcher.
* ''VideoGame/GihrensGreed'': zigzags with this trope. The price of a unit will not change even if the story (and your tech level) advances. The first time you try to build a Doros carrier, for example, will be astronomically expensive at that point of the game. Later on, there will be individual Mobile Suits that cost more than a Doros will, but there will also be other Suits (even new top of the line ones) which will cost less. Newly developed [[CharsCounterattack Jegans]] are still cheaper than building a second Zeta Gundam.

* ''{{Narbonic}}'' features an extended time-travel subplot which establishes that it is difficult, but not impossible, to change your own history. Physical time-travel takes all the energy that exists in the Universe [[spoiler: or, as it turns out, in some other universe that's just out of luck.]]
** Averted by another method that transfer your consciousness back or forward in time into your own body, and you can undergo changes as a result of altered behavior. For instance, Dave never smoked.
* Inverted in [[ this]] MelonPool strip. It's because of the OLD technology (engine) that required expensive fuel.