There is no comparison between an old Sportscoach and a $150,000 DP!! Your budget will bring you to a range of years that may have inherent problems. The worst one is Fiberglass walls that have checking. Look closely as there is no cure ! Some may have an ISL 400 with bad connecting rods. You can get the engine serial # and see if that powerplant is one of the bad ones. Make sure you get the service records. If it has been neglected you can spend $10,000 for tires and all fluids/filters/batteries. If you are patient that budget will get you a great unit! Enjoy!
Moisheh