Many of the products sold on eBay are items like laptops or mobile
phones or Xbox or computer memory - in other words, products which are
not scarce, which are available readily elsewhere and whose valuation
is commonly known and accepted. People go to eBay for such items not
to find a rare copy of that item, but because they are hoping to snag
a bargain. My question - what percentage of products sold on eBay (or
at least how many such products are sold on eBay over a timeframe of
say a week or a month) are products like these?