It has nothing to do with the amount. It's all about fucking the other guy.

I've done work in homes and overhead clients bragging to other owners about how much they fucked the contractor for. Like, they have conversations about it. And it'll be a few dozen grand on a multi million dollar home.

In one development there was a kind of club for these guys. They'd go and get drinks and just boast about who they fucked over and for how much. I know this because one of them was the contractor that got fucked. He was in on it. He actually played the game with them. He never really lost mo ey though. He'd just not pay the subs. It's OK though, he blew his brains out a few years ago so he doesn't play anymore.