Guild Wars 2

Reason being, listing expensive items for 1c under a seller needs to die off. If someone wants to undermine someone else’s sale by virtue of it being impossible not to buy theirs first, they should be forced to do it by a minimum percentage so that there is actually a drawback to this decision.

I’d also expect that this could become a thing for buy offers, although at least there is no fee to place an offer.

EDIT: The idea is that players do not continue to undercut forever because it is no longer profitable.

All this would do is make the price plummet as people undercut.