Frankly, I wouldn't be too concerned about the exhaust.
I'd have much more concern about the rust thru on the frame, the overall integrity of the frame, the poor condition of the brake and fuel lines. These 3 things alone make the truck an accident looking for a location.
A '97 vehicle with 250+ kmiles living in WI.........has had a good long service run, it may be time to retire it. The corollary is the spend $$$$ to fully replace the degraded parts, including frame. Or those $$$$ could be channeled into a ride in better condition, used or new.