This is a great idea but I don't think it could work. My immediate tactic was to put in 10 dollars each time until I saw the price dropping barely any lower. It

This is a great idea but I don't think it could work. My immediate tactic was to put in 10 dollars each time until I saw the price dropping barely any lower. It wouldn't take a non-technical person long to realise this aswell, so in practice, shops would probably just raise prices accordingly, and look uncompetitive if people compared the unnegoriated price. The difference with in person bartering is that you're dealing with a real person, who can walk away from a deal, and who has actualy emotions and needs. I don't care if I offend this computer with my ridiculous offers and I don't see the market stall owner with children to feed.