well if you know someone who can do it cheap it probably is worth getting fixed - whether its sand it back, cure it, bog it, paint it or putting on a new guard... body repairs can be very expensive (stupid insurance companies) and unless you are 'in the know' or know someone 'in the know' a buyer is going to factor in about 1k at least to get it fixed.....if you get a good job done for say 600$ thats better than dropping your price 1k....
(i know all about rust cause i own the worlds 2nd rustiest alfa romeo model after the sud .lol)