As an EFI veteran I will say EFI will cost more.
Properly tuned, the two will have comparable numbers. The differences will be in cold start and the EFI always refining its tune for the conditions.
As someone who is fuel injecting the flathead in his 51 Plymouth, the microsquirt controller alone costs more than two new 1bbl carbs, much less all the other stuff EFI needs. I have a spread sheet going detailing most of the expenditures. But my setup can also control the ignition, something a carb can't, it will also be able to compensate for alcohol in the gas, something a carb can't. So there are some additional benefits to EFI that a carb cannot match.
