It's a odd suggestion but I've asked around and people think it's a good idea. Normal auction house and street stall is maxed to 1bil so I'd suggest one with moolah as the currency so you don't have to constantly spam mega cause a lot of people don't have gold and moolah isn't what it used to be so a lot of people hold on to it , so this way they could find items and buy or sell straight up in moolah.

I don't know how hard it would be todo but worth a try