Depends what his goal is. If he plans to keep it for 20 more years, then yes, a new frame is probably the only answer, but cutting out and replacing the bad areas, along with diligent upkeep, and recoating the frame inside (as much as possible), will probably keep it together as long as he wishes to keep the vehicle, or at least as long as it stays running. There are no free rides... you either work on/maintain a cheaper, older vehicle you like, or pay big bucks to have a new one, that very quickly degrades to a “used” vehicle anyway... I hate having to worry about the frame rust living in the northeast (salt), but I paid cash a couple years ago for my truck, and still love it, so I do things as needed to keep it alive as long as I can. Bottom line is the extra work is WAY less than dealing with hefty payments every month, at least for me.