I'd have to say that this falls in the category of
"whatever someone wants to pay you over melt value"
1)You can't redeem it (the casino doesn't accept it anymore)
2)AFAIK, It doesn't have any rarity of error
Melt value is about $18.75 (.75 ozt. silver)
Someone from Louisiana might want it, but I don't know what they'd pay you for it.