You could keep the insurance claim money for roof replacement, do the repair yourself and sell the unit for about half way between the 2 trade in values. Just be upfront with the buyers about the problem, not cost, and the reasons for wanting a larger unit. You may be selling someone else dream deal.
I have sold a TC and a TT with roof problems. The TT had hail damage on a 18 yr old with alum roof. Just dented up but with the age the insurance totaled it. A yr later I bought a 5er and sold the the TT to the first couple that looked at it. $3,000 insurance and I kept the TT then sold for $2,600 not bad for a 18 yr old TT with single slide. I told them everything we had fixed over the years, showed them the roof and even told the guy who was taller than me that I always hit my head on the slide.
I bought a popup TC with a damaged roof and fixed it myself. I used to have pics of the repair on here and included the address in the ad. Took one trip to Alaska and sold it in less than a yr after I bought it. It was always planned to be a one trip wonder. Again the first people to look at it bought it. $650 purchase and sold for $1,300.
Both units were sold on Craigslist. The TC took 2 days to sell and the TT 12 hrs. I had thoughts of becoming a RV dealer, then the DW slapped me up side the head.