It's hard to find legitimate trade offers in the market, because the offer list is always spammed with dozens of offers like the following:
+3 Danish/Heavy Lance/Crossbow for anything else
Lowball gold and +1 offers for heirloom points
Lowball LP+gold offers for popular items
Booth owners buying LPs for ~20k less than they are selling them for
..etc
My proposition? Increase the listing fee to 1,000 gold, and include an option to hide booth offers (since these are the most likely to be "spam").
It would be nice to quickly find the players that are legitimately looking to swap gear, and filter out those simply trying to profit off the ignorance of others.