I have the Rottendog system 1 unit - used very lightly, only about a dozen games on it (replacing all the boards with an all-in-one from Pascal). Could do CAN$100 shipped (costed me just over $140 a couple weeks ago).
I also still have the original, but it needs a new IC1 (does have new caps, diodes, etc) but the 5 volt supply is toast (other voltages are ok).