There is a behavior set where sometimes people don't register that the price they put for an item is actually a relative loss to their gain from it. This is why I simply vendor certain items below a certain profit. I am still confused why certain items are present on the marketboard at all. But it is what it is. It's just un-ideal behavior of mass markets but you can earn money elsewhere, because this implies there's way too much supply for the item vs its demand.

Wouldn't be against buy orders, though, since it can inform what people actually want.

Don't craft items that are cheap on the MB if you're crafting them for the purpose of making a profit (as opposed to fun, achievements, convenience, whatever). I mean, that's obvious, of course, but if it needs to be mentioned.

There seems a decent amount of items that can be sold effectively for 50-100k gil, I don't feel that the market is broken at all, and I am just a sprout baby who scratched the surface and is barely paying attention.