Too me, if you're going to ask any kind of real money for something like this you should do all the work. Pull all the parts, get it sand-blasted, then take it to a frame builder and have it inspected. As-is, I agree $25 is all I'd throw at it on a bet.
When you read about how careful professional frame builders are about not over-heating a tube with just a localized torch, my gut feeling is this thing is going to have some issues.