Mercedes Benz repair: Rust Repair, visible rust, winshield

Question
I've got a sand dollar sized bit of rust where the bottom left of the back winshield meets the left side of the car.  How much do you think that would be to completely remove and repair.  I own a White 1985 300D Turbo.  Thanks.  

Answer
Rust can simple or it can be complicated. The area around the window might mean that the rear glass would have to be removed because the rust is probably in the channel underneath the rubber seal. You can most likely repair the visible rust very easily, but there is a strong likelyhood that it will come back unless you remove all the rust.