If those are the original tires then, they're over 31 years old. I wouldn't feel comfortable riding around on tires that old. Especially if there are a lot of big downhill runs nearby. It's also a small frame bike and, that's going to reduce the demand. So, with new tires, tubes, grease, brake pads, handlebar pads & maybe a new chain I think it would be worth somewhere between 5 or 6 hundred dollars US.