Should I keep EFI or put a carb on my 5.3 swap to save money?

It can be done: LS can run a carburetor: Edelbrock Performer RPM / Victor Jr. carb intakes, Holley options, and an MSD standalone ignition box for the coil-near-plug ignition. But look at the whole cost before assuming it's cheaper.

What a carb saves: a carb itself is generally cheaper to buy and maintain, and a carbureted setup can use a simple low-pressure pump and a single supply line.

What it costs you: a carb intake, a standalone ignition box for the LS coils, and giving up what EFI does well — precise fueling, easy cold starts, better economy and emissions, self-learning, and a sealed fuel system with no fuel smell.

What EFI costs: a high-pressure pump (preferably in-tank), filters, and a supply plus return line. LS EFI needs about 58 psi vs 5–7 psi for a carbureted small block; parts-store hose clamps/rubber hose are not adequate at 60 psi. Use AN hardlines, push-on hose/fittings, or ethanol-safe hose (e.g., Earl's Vapor Guard).

For a daily driver, EFI's cold starts, economy and drivability are hard to beat. If you still lean carb, price the intake and ignition box before deciding.