This was probably sold at the Old SF Mint which was sold to the city in 1993 to become a museum. The US Mint also sold medals depicting each of the Mint facilities. When I purchased mine in 2004, they sold for $2.25 each. Chris
A couple bucks is cool with me, got it in a lot for a few bucks. I love the reverse and am surprized the mint designers havn't taken notice. Maybe one day, thanx for the info...
The Old SF mint used to have a working coin press in one of the rooms where, after you paid a couple of bucks, they'd drop in a blank and you could strike your own medal by pressing a button. I don't know if this is one of those medals, largely because I don't remember the design, but it is certainly a possibility.