Paying a premium for a PSA 10
 

How much of a premium in percentage terms would everyone pay for the best PSA 10 they have seen of a card they want to buy?

The best centering, corners, and print quality seen anywhere.

A card with a minimum $500 value and pre 1985.

Are you asking how much a premium people would pay for a great looking PSA 10 vs an average PSA 10? Or when compared to the same card in a lower grade or ungraded?

Same grade.

I would say 10-20%, maybe slightly more if dead centered front and back on a card that's difficult to find centered.

If it's a modern card that is likely to have a still increasing pop, then no.

but if the card is an older card (like pre 1980), ten its unlikely more will appear, so I don't mind paying a little more for a PSA 10

I agree. I collect vintage cards so I answered with those in mind. But I still might pay a premium for a modern card if I thought I could cross it to a BGS 10.