I feel the same way you do on this topic in most ways, one time I asked a ebay seller after a certain part was listed for three years why hed not cut me a break vs spending the listing fees, well the big sellers pay zero or next to nothing for the listing, its the sale when ebay collects.

One ebay flipper/seller I despise because of his ways and prices but I just added up his overpriced listings sales for the past month, $6700 so people are buying his high priced parts and seem happy doing it.

At time I think rich people feel better about paying big money for a part vs getting a good deal.