The chip was a prototype made for the 1995 Tyson vs. McNeeley fight - Tyson's first fight after he got out of prison.

I heard a couple of reasons why the chip was never released - Tyson didn't like the low ($10) denomination, or he didn't like his picture on it. The MGM officially released two chips for the fight - a $25 and a $100.

I have one and bought/sold a few of these chips in the past. I would say a value would be somewhere between $30 to $50. I haven't seen any on for a while, so the price may be up (or down) from that.