It used to be pretty good for all 3 chips. However, in the last year or so they have been on eBay over and over again. Here's some sample sales with typical current (low) prices:

http://cgi.ebay.com/1-Casino-Chip-Colorado-River-Southpoint-Old-Obs-R-6-/170511059242?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item27b340492a

http://cgi.ebay.com/5-Casino-Chip-Colorado-River-Southpoint-Old-Obs-R-8-/180530833303?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a0879e797

http://cgi.ebay.com/25-Casino-Chip-Colorado-River-Southpoint-Old-Obs-R-8-/170511061297?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item27b3405131