The UX is poor. Haggling should be automatic. Make it an auction - allow everyone to post their offers and then the seller can take the offer they accept base

The UX is poor. Haggling should be automatic. Make it an auction - allow everyone to post their offers and then the seller can take the offer they accept based on price, location or whatever. To make it work, the offer has to be committed as long as it is posted. Hey, come to think of it, isn't this a description of how stock markets work? The ultimate haggling.