My approach too. Buy cables in six-packs and housing by the yard.

My cable inventory is larger than some because i have both Campy and Shimano brifters and they require different size end fittings for both the shift and brake cables. Jagwire makes double ended road derailleur cables with a Shimano button on one end and a Campy on the other and that simplifies it a bit. I guess I could file down the Shimano brake cable end fitting to fit the Campy levers but I buy the correct thing anyway.