I don't know where Dennis buys his tires, but a very good 22.5" tire from Hankook, Bridgestone or any other decent tire company will NOT cost you $4K or $5K. I bought Hankook AH-12 tires for our MH last fall and they were $400/ea mounted, out the door. The 19" tires would be less money than the 22½" tires. IMO, the so called RV tires from either Michelin or Goodyear are junk and many RVers will tell you the same thing.
That said, check the FRED suspension system, as I don't think it was air, but basically the same type leaf spring truck chassis as the Ford.
