I once spent $100 on a sort-of-similar bike in somewhat better condition, because it was exactly the model and size I was looking for. I spent maybe 30 hours and $300 getting it into the shape I wanted, and frankly, the seller was very fortunate to find a complete nut to sell it to.
So, if you find a complete nut, you might get $100 for it. Otherwise, somewhere between $20-$50, assuming everything works, more-or-less. That is to say, the cables, chain, and tires almost certainly need to be replaced before it can be ridden any distance, but if the relatively complicated rear hub is not in working condition, the value becomes almost nothing.