Found in "change"...

I guess you could call it "change." Buying a six-pack at the local
beer-and-wine shop, I happened a glance in the cash drawer. Sitting
by itself, in the left-hand receptacle, the one these places reserve
for the "weird" coins like Sackies, SBAs, Kennedys, etc, was what I
could see from 3-feet away was a Cameo Proof Half.

I asked the clerk if I could see it. He put his thumb on the face,
slid it up across the edge of the metal drawer, and handed it to me.

He was fine with accepting 50 cents for this now-slightly-impaired
1980-S Proof Kennedy.

....Tom