Roll Searching Found A Proof Coin

I do a lot of roll searching from rolls of Kennedys lately that I get a hundred bucks or so at a time from my bank.

I have set up with my banks that four times a month I come in and get rolls of coins for the purpose of just searching for good coins.

I use to do a lot of Lincoln Cents until my eyes felt like they were falling out of my head so I switch of now.
I have been doing Kennedy half and have been very lucky finding 40% and a few 90% 64's.
That's until two weeks ago I found a 1971 S (Clad) Proof in a roll!

It's not the first time I have found a proof coin in my change but most were nickes or quarters, never a half.

Now I know that a Proof Coin will always be a proof coin, but I have never ran across a proof that's been in circulation and I'm wondering if its of any value other than just a keep sake.






As you can see it has an ugly gash.

Just thought I would see what you folks think.