What is the value of a coin with no dates just a penny on one side and a dime on the other?

This is a magician's trick coin made from two legal tender coins. While you might be able to sell it on eBay for more than "face value" (one cent, 10¢ or 11¢), it has no numismatic value. It has no special value. They're manufactured for magicians. You can buy them at most magic shops.