[Exhibitman]

Of course it can and should be expected to happen: it is an Econ 101 concept, an imperfect substitute good. A substitute good is a good with demand that is increased when the price of another good is increased. Imperfect substitutes have a lesser level of substitutability. If you can’t afford a high grade 1952 Mantle, a lower grade card is an imperfect substitute with a fairly high level of substitutability. If you cannot afford even a beater 1952 Topps Mantle and you want a Mantle card, you might go for a decent 1956 Mantle instead. I think that is what is going on with a lot of collectors. Most of my Mantle cards are low to midgrade because I wasn’t going to pay for a high grade example.

As for other cards, it happens all the time, just not at the high $$/very public profile of the Mantles. When I decided to buy some early Ryan cards, I opted for a 1969 Topps Ryan in really nice condition instead of a 1968 Topps RC. I'd have done the same for Bench except I bought a collection that happened to have a Bench RC in it.