I regularly gig (well, used to) with a board full of home-made pedals. My basses are all bitsas, and my rack preamp is a home-made too.
This all goes into a shop-bought (shocker) power amp, into a home-made 1x12" cabinet with a tweeter.
Dunno what it's cost me over the years, but I'd put money on it being a hell of a lot less than shop-bought stuff!