I think you need to give us more details... type of unit, age, what type of damage? Depending on the damage, it might be better to sell as is. More information would be helpful.
"Fixin" what? If it's small scale repairs you can do yourself it's likely worth doing. If you have to pay someone to repair it the cost will exceed the value it adds to the TT so I wouldn't do it. The old repair or replace dilemma.