roland jx-305

could i expect to get for my roland jx-305 groovesynth? i bought it many moons ago and it's been fun to mess about with but i've got a whole whack of new gear and, for the right price i'd like to offload it. I believe it's basically an mc-505 but with keys. I have software which has pretty much replaced it in all basic functions, except for the odd synth sound which i like to record as audio. I'm sure it's not worth an awful lot but if the asking price is ridiculously low in comparison to what i payed for it (£500) i think i'll just hold onto it as a midi controller.