Quote Originally Posted by Sibyll View Post
Instead, it'll make people think more about how much they can afford to relist for while still making a profit.
The fastest way to make currency in any MMO, is to eliminate all your competitors. To have a monopoly of a market. With the listing fee, an individual can immediately place up a specific item at the minimal profit margin and force their competitor to either relist at a loss or wait until they decide that they no longer want to stay in that specific market.

Listing fees prevent relisting but it doesn't prevent the above from happening, the initial undercut.