I have a feeling there are some people in PR running a scam at the casino selling these chips to unsuspecting tourists at a huge discount. Something like "Mr, I was tipped this chip for caddying and I am not allowed in the casino...I will sell it to you for half off!" These guys buy the chips thinking they just made $500 and then realize they got took and try to dump it when they get back in the states. There is a name for this scam they they run often at banks and malls but I forgot what it is called.