I'd say it cheaper to buildup a carb'd engine, intakes are cheaper... add a better carb, cam, heads, +49 more CI.
EFI on the other hand, buy MAF, Injectors, Chip, Throttle body, a more expensive intake, heads, cam. Boost is a bit easier to come by though.
Meh, just my opinion on it... I'm biased though since I'm ditching EFI next year.