Posted By:
JimCrandellKing,
Fascinating that 1933 Goudey is also significantly less.
I think its likely that a big part of it is that people for some time have been trying to build high grade sets on the PSA Set Registry. Thus if you have a raw card which could 8 you could get more for it if you had PSA grade it.
Another explanation is that SGC seems to have a greater following among collectors who collect low-to-mid grade cards like a lot of people on this board(the armpit collectors)