I would guess $15-40 check out the Ebay link : http://www.ebay.com/sch/i.html?_trk...center&_nkw=off center&_sacat=41102&_from=R40 I am guessing yours is off-center by 5%. very cool find.
An off-center strike effects both sides of the coin. This is from a misaligned obverse die and it appears the coin also has a finned rim(thus the extra-thickness on one side). Neither is very rare, so you might get a couple of bucks for it.
I love the fact that you're holding the coin properly. Refreshing to see someone doing the right thing as opposed to a person smattering his mitt all over the coin.........
From what I have seen, this is pretty common...especially on 1971 Kennedy's. I don't think it's worth much. You might get a couple bucks for it...if you find the right buyer.