Though
ebay often has less experienced or amateur sellers, and items may be overpriced so they don't sell, what matters for assessing going value and comparison to CV and the prices from other non
ebay dealers are the items that actually sell. In a sense those that expect too much for common or less desirable material don't really count. Personally I ignore them completely as I expect most of us do when assessing what Should be paid for an item.
There's a Walmart aspect to
ebay, but there's also a portion that is higher quality. CV is far too out of whack from the market that probably has the most volume of sales.