How old is too old?

TALE OF WOE! Bought a 1997 Monoco Dynasty with an 8.3 Cummins with 59,000 miles from PPL Motorhomes in New Braunfels, Tx the middle of June. It looked well taken care inside and out. Picked it up on Wednesday and on Friday night we were on our way out West. Made it as far as Grant,New Mexico. This is my third MH (all from PPL). Had trouble holding it on tne road (thought it was wind)and when applying the air brakes the back end would try to come around. Got under it and all the trailing arms that hold the rear end in place did not have bushings in them (a common Monico problem according to Monico in Oregon). Contacted PPL and all they said was ("well,you made it 800 miles without a problem and you bought it as is".) Four days and $2200. later turned around and headed back since my son-in-law was in critical condition in ICU. Blew a tire outside of Socorro,NM and after four hours and $200. for a used tire made it to Las Cruses,NM where we spent the night. The next morning and $2700. later for six tires from Big O we headed home to San Antonio. Now, I can't get it to storage since I have no throttle response (electronic throttle).