found classic DOD fx56 distortion pedal

I need to know how much this could be worth. its was definately manufactured in the 80's and has a great classic metal fuzz sound. if someone else owns this pedal, maybe they could tell me how much they paid for theirs.

I have the FX55B Supra Distortion...paid 69 bucks new, but it sells for 39 new nowadays. I dont think DoD makes the FX56 anymore do they? Thats the American Metal pedal I think. Theres a couple on eBay going for around 20 bucks or so.

I dont really like my 55B, the battery dies rapidly and it just plain sounds bad. Its noisy and has quite a buzz to it. Almost like a ground problem, but even with a grounded power adapter plugged in it still buzzes.