In spite of that grade, it still looks pretty good in that slab. It ended up at just under $4000 which does seem a bit ridiculous.
I looked up some other PSA graded Mantles and it's clear that his Rookie is leaps and bounds above any other card. (Not too surprising.)
There is a '53 Bowman Color (beautiful card) PSA 5 that seems like it will end under $600.
I clearly don't put as much of a premium on the RC as other collectors though. I'd rather spend that $4000 on a whole host of better graded '50s Mantles.