Hello.
Welcome.You'll find that, for the most part, parts for the old Mustangs are very reasonably priced in comparison to most vintage cars.The cars aren't tremendously complicated to work on either.With a good set of basic hand tools and a couple of things like a torque wrench, timing light and volt meter a person that is mechanically inclined can easily perform most repair operations.Good luck on your new cars, and again, welcome.