The only reasons I don't have a classic Mustang (my favorites are 67-68 Fastbacks followed by 69-70 Fastbacks) is that they are ungodly expensive and far less reliable than the Mustang I currently own. They just cannot compete with the combination of performance, handling, reliability and economy of my current Mustang.
Next on my list would be a 66 or 67 Fairlane.
I'm of the age that I would rather drive it than work on it, so I remain content with what I have. Few of my friends still drive "hotrods"!