A 1956 Mantle headlines REA's auction

REA's September auction runs through the 20th.
The headline card is a 1956 Topps Mantle gray back in a PSA 8.5.
A PSA 9 of that same card sold for $414,800.
There is a 1962 Mays in an 8.5 too, and REA sold a PSA 9 of it for $369,000.
Over 90 complete and near complete sets are in the same auction.

Same money five years from now: one 1956 Mantle in an 8.5, or a modern 1 of 1?