[Mikendebbie]

If it is really cheap and you have no other choice...maybe.
I have bought used RVs in the past knowing I had some projects in front of me.
But a water leak...you don’t know how long it has been a problem. And the longer it has been a problem the more stuff can go to pot. Since Montana’s are aluminum framed walls the studs will be ok but the wall board could be damaged and I especially would worry if any of the screws holding the walls to the frame were rusted thru. No way to check that. I hate to be a Debbie downer but maybe someone else has better advice