Instead of deducting gold right away from the start when auctioning.
Could auctioning cost 0 gold but there is a certain deduction after item is sold.
If the item isn't sold, you don't lose gold. There could be 15% deduction after completing sell in auction.
This would increase the amount of items in auction of course, BUT there could be more options for what items you want. Such as buying items from a certain player by searching their name alongside item name.
Or info already on the item such as how much it usually sells for and who previously owned the item in a extra description for the very item. This idea could be improved if anyone else has extra auction options, I'm just wondering. I bet this has been suggested, but I wish to bring it up again just cause~ why Not? :P