Purchasing First RV- would like some advice...

any brand new/used if it has water stains? run no matter what. a very little stain could mean a huge rot area you can,t see. me I like buying used, just my opinion private sellers are more honest than a dealer sales person looking for a check. whats a salesmen know about a rv that was just traded in?? look long and hard when you find the one hire a rv mobil tech to check it out. they,ll give you there opinion of the rv. little cost but money well spent.