RE: Is this boat worth fixing up?
You're asking a very subjective question. Which is all the more difficult to answer with out actually being able to see the boat in question.
Reading your post I get the impression that you don't really want to fix it, you want to sell it. Please tell me if I'm wrong.
Could you get a couple hundred out of it as is? Maybe, if it came with running hardware, motor, Electronic Speed Control, receiver and transmitter. Then I would have to say most likely. Especially if you test it, and can verify that all the parts work correctly.
For just the boat itself, not very likely. Whoever buys it will have quite a project in refurbishment, repair, replace, refinish.