If this is too far off the subject, let me know.
Here is my reasoning for the EFI:
If you take the cost of a carburator (around $420-$480), plus the calibration kit ($60-$120)around , and add an O2 air/fuel meter ($160) you will have an easy $650-$750 into a basic carb setup that you still have to tune. If you have electric fans, a fan controller is around another $100.
Now your within <$250 of a $1,000 Sniper or Fitech EFI.
The EFI also comes with rev-limiters at no additional cost, and can also double as a gauge display of RPM, Engine Temp, Battery Voltage, just to name a few.
Now the fuel system for EFI might cost more if you have a good existing fuel system, but if your starting with a rusted fuel tank and lines, then the cost of replacing and setting up the fuel system is about the same.
The ignition can be the same for both, or you can lockout the distributor and re-phase the rotor and have the EFI control the ignition timing too.
The EFI can also do idle compensation for the Air Conditioner Clutch, and Control power adders while also adjusting the timing for them.
Anyhow, the EFI packs alot of features for not that much more money, and actually simplifies alot of wiring compared to individual gauges (O2 and such), and options like fan controller, rev-limiter, nitrous controller, and such.