I am holding 3 of these with the plan to cash them when I'm in Vegas in October. This auction (not mine) states that they are obsolete.

http://www.ebay.com/itm/25-MGM-Grand-Hotel-Casino-Las-Vegas-Casino-Chip-/320963089819?_trksid=p4012.m2036&_trkparms=aid%3D333005%26algo%3DRIC.FIT%26ao%3D1%26asc%3D25%26meid%3D1448607532678631975%26pid%3D100031%26prg%3D1019%26rk%3D3%26

Thank you for any help.