Any autographed baseball collectors out there?

My son and I have been collecting sports memorabelia for fifteen years with autographed pictures and cards from George Foreman to Nolan Ryan, but now we're looking at base. Check this out, it's autographed by Joe DeMaggio way back when he played for the Seals with stamped paperwork and all for 600. Is that a good deal? And do they have trading and gambling exhibits for base like they do for rare cards?