[jdmccright]

The truck you're looking at is only slightly newer yet alot more miles. If rust is an issue, I'd look for a even newer truck or look in an area where they don't salt the roads. They don't call it the rust belt for nothing....

There's surface rust that just looks bad and then there's rust that has penetrated a significant portion of the frame's thickness. The former can be cleaned up, repainted (albeit with alot of on-your-back effort) and then apply a good rubberized undercoat. If the rust is bad and in critical areas of the frame and body, move on.

This is the situation I have with my Dak...bought in PA and was too enamored to look underneath...idiot! Luckily, most of the rust damage is superficial and can be cleaned up with a power wire brush or dremel tool. I wouldn't rely on those "rust reformer" primers. They don't penetrate to convert the whole thickness (and some don't work at all!), leaving you with a thin converted coating atop the rest of the scaly rust. Wire brush/grind it off as much as possible, convert the rest, prime, paint, and undercoat. Good luck!