The original American Basketball Association may have disappeared, but ABA fans haven't. "There's a lot of people that are very – how would I say it – feverish about going after any significant pieces within that league," Kohler says. Julius Erving's 1974 New York Nets ABA Championship ring was perhaps the most significant of the lot. Largely because of Dr. J's enduring appeal, the piece sold for $460,741 in 2011 at an auction of Erving memorabilia that netted roughly $3.5 million. The ring features the ABA's signature red, white, and blue basketball with a diamond in the center, making it one of the few pieces of expensive memorabilia that would be extremely valuable without a backstory.