Water damage in potential buy

We're looking at a used 2019 rpod 172, but when I went to view it I noticed some minor water staining on the ceilingabove the dinette in the rear. There are a few spots spread across the width that are centered around where the staples holding up the interior are, as if water seeped out through the staple hole. There are also a few spots where the ceiling meets the walls on both sides. It is a bit below where the wind diverter is on the exterior, making me think that's the source of where water is getting in as there are no signs of water damage anywhere else. On the exterior it appears that everything around the wind diverter is still well sealed with the factory caulking (there's one tiny gap in it, about the size of a pencil point, but it's in one corner and seems unlikely it would cause staining on the opposite side). It's been sitting uncovered at the consignment dealership all winter in Montana and we've had lots of moisture, there was even a bit of water sitting on the top side of the wind diverter when I went to look at it, but on the inside nothing seems to be wet now, just stained. The seller claims he never saw any staining, so it's hard to tell how long it's been there or what the source is. 

It’s a valid question and depends a lot on if you are good with your hands or not. I had a big rain storm one night and the same thing happened. I could always smell a bit of a musky smell prior to me discovering a sagging ceiling. I put some tips up on this website/forum on how I repaired mine. It is due to the spoiler on the top where the screws go in to the gelcoat. I took the spoiler off and recaulked everything underneath. I then used Enterra bond tape and sealed the whole spoiler down again over the screws. I then cut the ceiling out and pulled out the insulation to dry it. I found the dealer had sheets of interior, wood, paneling, and cut a piece to fit back in. I did it all in a weekend. you could always try to lowball this person, but make sure to check underneath the trailer as well because the water will run down the sides inside the walls and end up on the floor section. Underneath the trailer you may find the wood buckling. It’s not a big deal. I also razor knife it out and put in plastic sheeting. personally, I think if the rest of the trailer is good, I would lowball the person and spend a bit of time doing the repair.