Undercutting

[MilkieTea]

Yeah you don't understand how it works at all.

Buy orders are not required to be filled. They're an option. No one would fill a stupidly low priced buy order, just like no one will buy a wind crystal priced at 999,999,999 gil.

Please read what they are replying to.

Only one way to get a definite end to undercutting. Buy orders.

AKA: Someone makes a request for an item for x amount of gil, and no one can sell below that amount until that buy order is fulfilled.
That way it would be significantly harder for someone to crash the value of items by grossly undercutting them.