I purchased a Bung Xchanger and two 64M carts to try and get into making chiptunes, without realizing that I needed a parallel port to transfer roms. One of the carts has a dead battery, which is fairly simple to replace, and the other works just fine.
I'm mostly looking for one of those new drag 'n' derp carts, or a couple of EMS carts, but I'm open to all offers.