is ebay killing high grade 50's-60's market?

[ebrehm]

Here is what PSA states regarding valuation of cards that have not yet been graded; I assume the same logic would carry over to cards that do not exist in particular grades:

Cards Not Yet Graded or Few Known

In cases where a card has not yet been graded or in cases where a card is extremely scarce and rarely comes up for sale, we do our best to give conservative estimates for those cards. We try to compare that card to other comparable rarities in order to come up with a price but our stance at SMR is that a card is worth what someone is willing to pay so we try to avoid speculating too much and focus on actual sales. If you know of a rarity that has sold privately and it can be verified, let us know. We can’t make changes if we don’t have the pertinent information.