I think its strange that a breeder would have such a bad shed. Not seeing the pics I would stay away because.....well, I don't trust anyone and that just sounds fishy.
After seeing the pics if it was obvious the skin was never going to be normal again I would also pass unless we are talking dirt cheap pricing. If it appears there is a chance of it being normal or close to normal I would be more inclined to take the chance, especially if it was something I needed in a breeding program but even then I am not willing to gamble to much money and would want a major price reduction.
Im interested to see the pics, both before and after.