I think it depends on what setup you currently have and what you're going to. If you already have carbs, an ITB/EFI setup even on the cheap is going to be a lot more expensive than repairing your carbs as you're going to need to swap fuel pumps, possibly the fuel tank, pick out an ECU, tune it, etc.
My Webers were leaking everywhere and, after struggling to get a local shop able and with time on their schedule to repair/tune them, decided it was now or never to go EFI. I spent roughly $15,000 (with a bunch of other "while we're in there" costs) for my conversion, which included a brand new fuel tank, new fuel pump, new lines, pressure regulator, Clewett ITBs, coil-on-plug conversion, ECU Masters Black Emu ECU, new wiring, cam sensor, crank sensor/trigger wheel, then ultimately a dyno tune and probably a few other items I forgot.
I know there are a lot of DIYers here which could likely have cut my cost in half so that's obviously a consideration if you aren't a ham-fisted home mechanic like myself. I also get that not all conversions are going to include revamping the entire ignition system.
I'm guessing rebuilding and tuning the Webers would have run me a few grand by comparison.
A before and after:
