Well, I am not really a postwar or high grade collector but I have followed a few auctions before and use ebay to buy, extensively. I think Adam hit the nail on the head.
If you can go find the card tomorrow, and cash is short today (as it is for a lot of us), then you put off that buy unless it's a steal ie...a few of the sales listed in the first post. If I were a high grade 50's - 70's collector I would still have some worry that many more of my valuable PSA 9, 1 of 1 cards would come to surface. I am sure a 1 of 5 goes for less than a 1 of 1. I wonder how many unopened cases the Fritsch family still has?
In the pre-war space it's about true rarity and not pop reports. I still get a chuckle when someone asks me about many of my rare cards and ask the pop report on them. I usually just tell them the pop is
snap-crackle and move on.
They obviously don't understand pre-war (WWII)......
edited to add that I am NOT putting down the way anyone collects...if they want to go for high grade post war it is their money...If they have fun collecting that way who am I to rain on their parade?...Hey, who knows, their way might be better in the long run!! (it's not a philosophy I share though)