Basic complete (I mean complete) Bell cable kit from Asda for £4!!!
I used this on my commuter, good value for money - But note there are some short cuts taken to get it down to this price. Primarily the cable outers aren't plastic lined, meaning you have to grease them and they're not quite as smooth as more expensive cables, although they still work perfectly well.
Secondly, the gear outers aren't compression-less cable - They're actually just brake outer, so indexed shifting may not be as snappy as you'd like. The kit is perfect for use on a workhorse commuter bike but possibly not your Sunday best!
That said the kit does also come with a good selection of ferrules, cable ends, and even the little metal cable stop for old non-aero road levers!