[Steve D]

I would say there is some merit to that argument, but not much.

If it were true, then why do PSA/SGC graded cards, with nice big, clear scans of both front and back, from known reputable sellers, still bring prices that are significantly below what B&M shop owners charge.

To me, the biggest reason for B&M shop owners charging "higher than ebay" prices, is the fact that they must be able to pay rent/utilities/employee salaries/etc for their shop. Ebay sellers don't need to do this, as for the most part, they're selling from their living room/den/mancave. So basically, ebay sellers have a huge built-in advantage.

Steve