I say remove the physical manefestations of the wards, make all retainers searchable by the items they sell but when you buy the item you have to see all their inventory first, That way the "Browsing to see what you have" part is still there
And no, turning the Physical Market Wards into a Menu Market system does not make it an Auction House.
Its only an auction house if you add Timed or Blind Bidding.
No Bidding = Not an Auction House.
Also Price histories are abusable by RMT