I have one of these coins too. Looking for more info.
If this is the coin, there is one listed on Ebay for $125.00.
http://www.ebay.com/itm/Vintage-Jack-Charlies-21-Club-HEADS-TAILS-TOKEN-Pig-Butt-New-York-City-/131070328761
Not much monetary value, but still a collectible.
The OP should post a pic, since there are many versions of a 21 token.
Can't speak for the latest token holder, but I can't post a pic. No camera. The front side of my token is the same as shown. The reverse is slightly different. It has the squiggle and "21." It also has an arrow with the words, "All right. You pay" inside the arrow.
I doubt if it comes even close to $125 in value. It's tarnished, and condition is key.