£5,000 spent sorting out damp wood to no avail

Rustle

First, I'm sorry if there's another thread on this but I haven't found one on searching.

We have a2007 Elddis Sunseeker 120 (same as an Autoquest 120) and for the first time last January the damp report was not good. Took it for repair, the bill grew until it was almost £5,000 and I hoped that was it. Just had another habitation service done
and damp is not fully resolved (the dealer doesn't carry out damp repairs so not down to them) with readings over 30 where the main problem was.

My dilemma is do I

1. Do nothing and run it until it's beyond repair

2. Have another repair job done

3. Buy another motorhome

If option 3, which is the best brand as far as wood rot is concerned?