I think 911's in general, SC's and Carreras are a bargain when you compair their costs over any other Classic cars / Street Rod's / Harley's/ etc. They have a higher leavel of build quality than most other cars of their era also.
They are more useful and drivable than most other toys.
Like the old Porshe ads used to say "Take it to the track on Sunday and to work on Monday".