There are a number of possible sources, none of which will give you an absolute price. I use numismedia (http://www.numismedia.com/ ), auction results from Heritage ( http://coins.ha.com/common/auctions/?ic=Tab-Auctions-041408 ) and Teletrade (http://www.teletrade.com/coins/ ) , StacksBowers http://stacksbowers.com/). You want to also search eBay for completed auction activity ( http://www.ebay.com/) . You first need to learn to grade old copper, then do some homework to see what similarly graded coins have sold for, then you will be in a good position to estimate the value of your items.
