For this reason, I won't even get "repros" of games that were ever actually in print. The only ones I buy are multi-carts and fan hacks.
The one exception, I have sold some copies of Mega-Man Wily Wars for Genesis, which was technically released on the Mega-Drive. None the less, since I sell it in a custom box for $20 bucks, it should be obvious...however, I will also gleefully point it out.