slight rust on cab corner

Hey-
what are your suggestions here- ive got a 97 k1500 ext cab with 3rd door. Its got a little rust on the left rear cab corner. the paint is starting to chip off a little bit, and theres a small hole between the cab and bed of the truck, nothing major though. a local body shop quoted me $700 to fix it, said they have to slide the bed back and take the 3rd door off. Wondering what I can do myself before it gets really bad, then ill drop the coin to have a new cab corner put on.
thanks
-Zach

I used to work at a body shop and honestly $700 doesn't sound bad. However i don't know how bad the rust damage is. My guess is it is actually worse than you think. You may only see a size of lets say a quarter but if you starting stripping the paint you might find its really a spot the size of a doller bill that needs to be adressed. Rust is like cancer, it spreads and you can't always see all of it.
If you really want to try repairing it yourself I hope you know how to weld REAL good. And yes to do it (correctly) you will have to move the bed back so you can paint it (correctly). Just remember you get what you pay for. $700 may actually be an underbid just to get your business and give you minimal quality.