I'll agree that a PSA 10 out sells SGC 10 by a good range. On eBay I have sold the SGC 9.5 in the same range as a PSA 9, the gap, from what I've seen, is not SGC 10 = PSA 7 for the entirely of the Sports Card market, but you may find instances where that is true. PSA has the publicity and numbers, but IMO, SGC, CSG and Beckett all grade tougher than PSA. Not enough for the average person to take notice. For me, it's about the card, as we saw with the recent SGC Babe Ruth card selling for $6 million.