The '52 Topps Mantle is the Wagner / grail card of the Baby Boomer set. It's fascinating to me how grading and the craze of the modern hobby have continued to push the price of this card up in recent years. I started collecting as a kid in 1986 and used to persuade my mother to buy vintage cards for me at the local shops back when $20 or so for a nice '66 Koufax (still one of my favorites) was considered BIG MONEY.
I guess I should have been more persuasive back then when a mid-grade '52 #311 went for "only" a couple of thousand dollars. Hey ma, do you know what this card will be worth in 2015?? The sad thing is, I was doing that kind of persuading back then - but alas, for complete sets of '89 UD and 1990 Donruss and that kind of thing. Doh!