The Price is Right is a Goodson-Todman Game Show, created in 1956 with Paul Alter directing and Bill Cullen as host, asking four contestants to look at a given prize and guess its actual retail price; whichever contestant guessed the closest without overbidding won the prize. This format ran in daytime and nighttime on NBC and later ABC from 1956 to 1965 (moving to the latter in September 1963). This original incarnation of the shownote was pastiched in a famous episode of The Flintstones.
The more familiar format, with the Catchphrase "Come on down!", debuted in 1972... but the story of how it got on the air is a bit odd. Goodson initially wanted to bring the show back as a weekly, prime-time syndicated series with Cullen as host, but those talks fell through at around the end of January. Goodson's next choice was Dennis James, who'd caught his eye by filling in on Let's Make a Deal; Goodson and James recorded a pitch film on February 16 for the New show, distributed by Viacom, sharing ideas and concepts that had elements of what was to come.note
Around mid-May, while the new format was being hammered out (one suggestion was to use three Showcases), CBS daytime programming chief Bud Grant expressed interest in a five-a-week daytime version (along with two other new shows, The Joker's Wild and Gambit) and selected Bob Barker to host it... but Barker wanted no part of it and felt the show could be better produced, begging Grant to let him host one of the other shows. (It's been speculated that Barker simply wanted to stick with his strengths by hosting a quiz-based game show, as he'd been doing on Truth or Consequences for the previous 15+ years.) Grant responded by telling him that while the other two shows had mere "traffic cop" roles for their hosts, Barker had "far more talent" than that (unwittingly insulting eventual hosts Jack Barry and Wink Martindale in the process).
Premiering on September 4, 1972, the daytime series can still be seen on CBS, with the concurrent nighttime show airing until 1980 (Barker replaced James in 1977). Other concurrent syndicated series starred Tom Kennedy (1985-86) and Doug Davidson (1994-95). This format added two new elements: contestants are now chosen from the Studio Audience, and the winner of each item up for bids joins the host onstage to play one of dozens of pricing games. The hour-long format for Price was tried for the week of September 8, 1975 and became permanent on November 3. Johnny Olson was the CBS version's initial caller of the phrase "Come on down" until his 1985 death, at which point Rod Roddy replaced him following a rotation of substitutes. Another rotation followed Rod's 2003 death, resulting in Rich Fields becoming the show's third announcer. In addition, the show's rotating cast of models ("Barker's Beauties") provided a larger cast of characters to draw from. As a one-hour daytime show, Price was at its peak for a long period of time, becoming a fixture for stay-at-home moms, children home sick from school, and college students, garnering a fandom of all ages while making household names of Barker and Roddy.
After starting his 35th year with the show, Barker announced his retirement from TV at the end of October 2006; his final show aired June 15, 2007, and Drew Carey succeeded him on October 15. Carey had already cut his teeth in the game show hosting field for CBS with Power of 10. Fields left the show in 2010, and a third rotation of substitutes ensued until fellow Whose Line Is It Anyway? colleague (and former The Weakest Link host) George Gray replaced him.
The show has been made in many other countries, such as the United Kingdom from 1984-2007 (with hosts including Leslie Crowther [who notably called the contestants to "Come on Down" himself, rather than having The Announcer do it] and the legendary Bruce Forsyth) and Australia (which featured versions hosted by Ian Turpie and Larry Emdur, although there were versions prior to these, including several short-lived adaptations of the original Bill Cullen format).