I came up on four copies of Marley Marl Scratch one day, all for like a couple of dollars each. I sold one, hooked my boy up with one, and kept two for my self. One VG+ and one sealed with a 'Love that Wiz' sticker on it. You've probably all heard the regular version so check the Demo version.
Anyone who met Bobby Nystrom from the NY Islanders at this Wiz grand opening in 1986 will get a free mix CD courtesy of DW.