When you have A) a customer who isn't looking for a bargain, and B) a seller who cares about their reputation – then doing business is a pleasure for both parties and very smooth.

If you're the seller, then it's easy to filter out customers who don't fit into category A, with pricing. For the customer it's harder to filter out sellers who don't fit into category B, but generally you won't find them if you're looking for a bargain.