What he said.You can search through the group as it has been posted before. Someone posted the advertisement in one of the previous threads. They were sold at a profit to commemorate JFK. I can't remember the price exactly, but I think they sold them for about $5/each (in early 80's money that was a hefty premium).
See here: http://www.treasurenet.com/forums/coin-roll-hunting/77627-jfk-half-dollars-1960-1980-stamped-them.html
Kinda interesting...