Factory EFI A body conversion

I'm running a magnum, and was thinking that this would be a cost effective way to go fuel injection. My cam will likely change in the future, I already run a knock off air gap intake and thought about having it modified. It is beginning to look like cost wise it will be fairly close to, if not more expensive than a off the shelf self learning tbi unit. Had I done this from the get - go I would have bought a wrecked truck with everything. I had the space to store a donor vehicle for stripping then, but now I only have space for my car.