Korg Mono/Poly

I'm jsut not using the monopoly enough to warrant keeping it, i
wondering if anyone can give me an idea of what i should be asking for
it please.

Its in full working condition (except the keys which dont always
trigger, but i will repair this before selling), front panel is clean,
bottom front end of one of the fake wood sides has a little of the
plastic missing.

So a pretty clean machine, whats it worth?

regards

Paul