[michaelt]

If you want academic support for "if everyone else cheats and gets away with it, you'll have to cheat too" you might enjoy The Market for Lemons [1]

This argues that, if 50% of used cars are good and worth $8000, and 50% are bad and worth $4000, and customers can't tell them apart on the lot, the buyers' expected value is $6000 so the sellers of good cars will make a loss and go out of business. That in turn will reduce the buyers' expected value to $4000.

Obviously, that issue is specific to markets without seller reputations, reliable independent reviews, useful warranties, or effective consumer protection laws. Is Amazon Marketplace that way? You be the judge!

[1] https://en.wikipedia.org/wiki/The_Market_for_Lemons