Check the lower rear corners for rot. Also, check the rear wheel well areas for rust. GM put in some short side window drains and all water drains in between the interior and exterior sheet metal. Check your rear fenders. Not as hard to find as the other Suburban specific items, but a lot harder than the truck version. I believe there is still one vendor making them out of fiberglass. The drivers side that came with mine looked great from a distance. 1/2" of bondo will do that. Otherwise, for what you have described, I can agree with the previously stated estimations.
