Normal player can't sit in front of auction house all day long re-listing auctions, normal players would rather be out in the world - that's the major difference between retail and Classic. This will lead to fully automated AH sniping, 1 copper undercutting, AH camping 24/7, which will have negative effect on players. However Classic is based on new version of WoW, where auction house add-ons exist and they can be automated so much that they behave like auction house bots. In vanilla auction house UI was not accessible for third party add-ons, so everything had to be done manually.
