it would be cheaper if you built it yourself. that's the whole reason the ms is supposed to be so inexpensive. why do you have two wire kits? if you're using the relay board you just get the harness to go between the relay board and the MS. the regular wire kit is for people not using the relay board. if you don't use the relay board all your wiring from the engine bay goes straight to the MS. if you have a relay board, the relay board is hooked up to the MS via the cable and all your wiring terminates at the relay board in the engine bay.

if you want to save more money you could do without the relay board.

and i think it's pretty safe to say you'll get a couple CEL codes when using the MS... your ecu thinks it doesn't have any injectors.

-marc