I tried to get Mel to explain it to me once but it was not very clear. I belive it s a two-metal alloy, though... no plating involved. In my opinion, it makes for very ugly chips, probably why few were ever made this way. The Trocadero chips are the same construction.

Top of the Vine chips are pretty common and don't bring a big price. A few of the odd denominations like the $3.50 I showed are scarce. I'd say your value for the dollar is about right.