I could very well be wrong, but it seems like most/all of these chips are fantasy/commemorative. Not just yours, but the hundreds, or thousands, of others that have been bought/sold here.

Some are going for very good money too..$20, $30 each for some of them. Since I'm sure most of these have never been offered before, people are buying them as they would buy art..or as any "collectible". I just hope people that are buying them know they aren't real casino chips..