Interesting... I mean if you could build a virtually new engine... Lots of benefits here.
I would rather spend that money fixing an air cooled 911 than buying something more modern
Not all on the engine mind you but the car as a whole.
It would be reliable and frugal if you invested in a good (sensible) after-market EFI system to help with fuel economy.
Why not update a bit? Also... You'd have a sleeper capable of out performing most other cars on the road.
Thought of this way a 911 suddenly becomes one of the most economical cars on the road.
BTW: I know a lot of people who would spend $30,000 on crap they don't need, a "cheap" Korean 4x4 or a second hand Toyota/Lexus.