Buy Everything at Once or Piece Together

Theoretical question: let’s say you want to convert from an auto to a 4 speed. You find a complete 4 speed changeover for YOUR car: transmission with rods, Z Bar, shifter, handle, bellhousing, new clutch kit, pedals, hump maybe even a steering column. But it’s a couple of hundred more than what you have available. So what do you do: pass on it and start piecing the conversion together as you find the individual pieces and can afford it OR somehow scrap the money together and buy the complete changeover at the same time OR even though the seller says will not separate, make an that the seller just can’t refuse on the part(s) you need to complete the conversion.

As I said just a theoretical question as I’ve never came across a complete 4 speed conversion, just parts here and there.