Are all BTN stupid or is it just on my server?

[Jojoya]

But completely crashing it in 12 hours is stupidity. And I have an economics degree before you go on about how economies work.

A real life economics degree isn't going to be much help in an online video game where people make random decisions for random reasons.

Most of the crashing is thanks to the bots, not real players. They will vigorously undercut each other because they don't really care. Their time is free.

Time has value and is not that hard to calculate gil per hour from different activities. So yes, selling at a loss is a thing because "opportunity cost" is also a thing.

Only if you care about such things. In a game, not everyone does.