I have a wizard 5 hp motor my dad bought in 1954. Motor hasn't been used in about 30 years. I have the original stand, gas tank, and owner's manual (untouched for 50 years). Does anyone know how much this would be worth?
Questions on value are always very subjective, and there are a lot of factors that go into determining value. If you have one in mint or near-mint condition with good original paint, decals, and the accessories, several hundred dollars isn't out of the question....especially if it runs. The run of the mill motors you see of this vintage usually look pretty rough if used a lot, but if they run, you might be able to get $100.
Your best bet it to take a look at motors of similar vintage and condition on ebay and see what they are going for. That's usually a good indicator of price. If you can sell it locally without the ridiculous shipping charges, you might be able to get a little extra.
Just my 2 cents! If you're serious about selling, you might want to consider the AOMCI.org web page (see "free classifieds" link).