This sh*t again...

You have the Market Wards.
You have the Item Search feature.

That's ENOUGH for everyone who wants an "Auction House". Are you telling me that going into the right ward and finding the retainer is a pain in the neck? Well duh, it's a motherloving Market Ward. So that means to go to the vendor and buy sh*t from him. And for finding the retainer being a problem... follow the gigantic red star and the red dot on the map?

If you really wanted a little ease to better the Market Wards, they could implement a thing in the Item Search feature where when listed the retainers you can select one and port in its ward/before its feet.

And by the way, if you want an Auction House, you want an Auction House, which means placing bids and concurring with other players, not just lolbuy. Check eBay for example.