Leaking at roof seam, common in class B's?

My class A leaked and rotted out the whole passengers side 34 foot. I replaced the whole side, all new plywood. I did not have any mold on the inside. Go look at it and see how bad it is, might just be a little leak that can be fixed easy. My class B had a few drops coming in around the window on the roof when I bought it, not enough to cause any mold and a quick fix. Sounds like a good price.

I've resealed my roof seam in several stretches. It's not too hard. I had some drips entering by the front doors which drew my attention, and a poster on here who had the same rv who had done the repair to guide me through the process.

I have a feeling that once you got into the interiors walls...rust will be all rampant. Me personally, I would pass, and continue your search. I see they use a dehumidifier inside...once you own it and are driving around, that musky odor will really be ripe. They say it is in the seams, it could be around the overhead lights, ceiling fan.....some or all. Safe travels.

Was my thought too, but thought I should at least ask
Thanks

roof leak? run, you have no way of knowing how much damage there is.