Proof Sets should have the "S" mint mark. I agree that it is probably plated, just like the 24K gold ones, and the hologram ones, and the platinum ones, etc. Even eBayers do not pay much more than market value of the original UNC coin......... if even that.
NOTE: If your friend got it in change, chances are that it was pilfered from a set by a kid, and spent.
Edited by johne3797
03/06/2008 09:20 am