Through the Eyes of Madness: Sam does seem to be struggling with some mix of depression and paranoia, so his inner narration as well as outward behavior throughout the film are quite skewed. He rants about how the American dream has failed and that it's impossible for him to get ahead in life. Stand back and analyze the film for a moment: he's actually a reasonably successful salesman, and his boss commends him on having the highest annual sales in the office. But he absolutely hates his job and his boss is very annoying, so he keeps pursuing implausible plans to start his own mobile tire-selling truck. He also frequently rants about how he loathes his job on general principle, because as a salesman he is required to lie... in which case, why the hell did he become a salesman in the first place? He imagines that the world is out to crush him and is devastated that "the American dream has failed" because his wife left him with their children...when she really left him due to his own bizarre behavior. The film isn't a Fight Club style look at a man crushed by the System. It's a film about a mentally ill man who increasingly blames everything around him for his own untreated behavior.
Moved this here:
Now I've never seen the film, but is this actually a valid example? It reads like someone's Alternative Character Interpretation or Wild Mass Guessing. Additionally, Unreliable Narrator would more likely apply if it in fact is; Through the Eyes of Madness is for characters who are clinically insane or hallucinating.
You've got roaming bands of armed, aggressive, tyrannical plumbers coming to your door, saying "Use our service, or else!"