hey Scrawny and welcome to CoinTalk! That 1971 D is in pretty good shape and worth hanging onto, but it is probably only worth face value right now due to the fact that there were so many minted that year. Not sure how many off hand but I know it is one of the more common date Kennedy's that I regularly find while searching. Keep on looking though, there are lot's of hidden gems out there!
Or you could grind off the reverse clad layer and try to sell it on eBay for this ridiculous amount: http://www.ebay.com/itm/1971-D-Kenn...09?pt=Coins_US_Individual&hash=item43ab3c9651
302,097,424 making it most common, worth face, and heavily circulated as well. Jloring, if that seller can't tell that is PMD and not worth anything, due to the circular effect of the reverse which would indicate possibly being placed in a lathe, then they should take up butterfly collecting.
