2000 Suburban 2500?

I am looking at a 2000 Suburban 2500 4x4 LT with about 165K miles, but it has a few issues. The rear main seal needs replacing, which alot of suburbans need, the 4x4 switch needs to be replaced, and the AC for some reason blows out the defrost. I researched all the issues and the only one that seems tricky is the AC issue. Being as I am in AZ it is hard to deal with no AC comming out the front vents. Anyway the guy is asking $5500 and I know he needs to get rid of it. The interior is fair, the exterior is good, the engine is very good, and it has pretty much brand new tires. It is deffinately set up to tow as it has the heavy duty tranny and tow package. Just wanting some thoughts.