Mark McGwire 1998 70th Home Run Ball

Mark McGwire of the St.Louis Cardinals set the single-season home run record with 70 during the 1998 Major League Baseball season. Todd McFarlane, a comic book artist, bought the baseball for well over $3 million shortly after McGwire hit that historic home run.

It turned out that wasn't the best decision. Several sports memorabilia auction houses, according to TMZ Sports, estimate McGwire's home run ball to be worth as little as $250,000. On the low end of the spectrum, Goldin Auctions' Ken Goldin estimated McGwire's then-record-setting ball to be worth $250,000 to $300,000. SCP Auctions' David Kohler gave it the same minimum value, but said it may be worth up to $400,000. However, it is still considered as one of the most expensive collectibles.

Price: $3.05 million