I certainly wouldn't pass up a well priced 18 year old camper if it was what I wanted.
Hell if the failure hasn't happened in 18 years it ain't going to happen if the trailer has lots of towing miles.
Another point is maybe the unit already has the recall work done.
Can it be fixed at a reasonable price ?? Much depends as much depends on the shop doing the work. The shop that did mine charged just over 600 bucks. That included dropping the underside filon panel.....reinforcing the structure....buttoning and resealing the filon panel. That was in '03 and prices are higher now IMO.