Forget trying to decide what the bike may be worth. The real question is do you want a cheap, basic ride, or are you willing to spend a bit for one to donate. If the wheels are true, the rubber and cables sound, and all it needs is a rear derailleur and some fine tuning then it's a good candidate for a cheap ride. If it needs anything that takes the word cheap out of the equation, it isn't.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.