Well it's also the environment- ebay is not a very efficient marketplace, well in my opinion. Playing the pure "compare prices" game can get out of whack because ebay is so large and complex. The many categories make it so that one vintage part might find great exposure, while another gets little simply because the search engine or category parameters may overlook it. The prices would then be quite different, even assuming the parts were the same. I will also add on a personal note that the newer search functions on ebay seem to have actually made this somewhat more of a pain. That is just personal experience though.