99 newmar mountain aire 4081 prepare for towing

Why would it worth less than $5k? These are up for sale between $30-40k when it’s original, everything is old. I was planning to make it more like modern looking on the inside for my family and not for business. I think few grand in material would do it. The diesel generator started right up. That’s good. Now I have to figure out what’s missing around the engine.