What's it worth?

I cleaned up and serviced my father-in-laws Ingersoll 4016 last summer and was thinking of selling it. I've been poking around trying to find what it might be worth and prices are all over the place. It's a 1993 and has a 44" deck that goes with it and has 654 hrs. on the meter, it has the 16 hp Vanguard. The paint is original and in great shape with a few deep scratches on the left fender from getting on and off and the wheels have a little rust. Completely serviced and gone over, belts will be new when I put the deck back on.

Was hoping to get a little insight on a fair price to ask for it? I wouldn't mind keeping it but really have no need for it, I have a pretty small lawn. Any help would be great... and thank you!!