A lot of us late model purchaser's have delt with the corrosion problem to some degree or another, we be included.
In our case it has progressed to a point and seems to have stabilized. No noticeable occurrances the last few seasons.... Knock on wood.
All of the cosmetic remedies have been DIY, as the factory is corrosion impaired,
If it is a well maintained unit and out of the salt air you may be good to go,
read carefully the above linked threads, a gently used is the way to go IMHO.
Bob