You might be cheaper piecing together the equipment for yourself - I seem to remember a lot of the starter kits being quite expensive as they come with brand new cornies, not reconditioned ones. Might be wrong though. You'll also need a fridge to put them.
For a complete setup, you'll need the following (assuming 2 kegs):
-Fridge (big enough for at least 2 kegs)
-CO2
-CO2 regulator
-2 corny kegs
-Beer and gas lines (3/8" is what I use; length depending on personal requirements)
-2 gas quick disconnects with John Guest push fittings
-2 liquid quick disconnects with John Guest push fittings
-2 beer taps
-2 4" tap shanks
-2 John Guest 3/8" push fit to 5/8" BSP thread
-John Guest Y splitter
I pieced mine together for <£200 in total. Fridge was second hand from GumTree at £25 and the CO2 cylinder was a surplus fire extinguisher from work. The 2 cornies I got from The Home Brew Company in Ireland, as they were the best priced A grade reconditioned kegs available at the time ~£100 for the pair. I also kept costs down by replacing the typical gas manifold (~£35) with a Y splitter (splits the single gas line to feed both kegs)
Everything else was new from Home Brew Online. The guys on the phone were really helpful and even advised on beer line length (3-4m per keg).
You could keg a beer for dirt cheap, i.e. keg not refrigerated, picnic tap dispenser, a cheap regulator with CO2 bulbs, etc. But it would be *****. You'd end up sticking all that gear in a box somewhere just to then go out and buy nice taps, a good regulator, etc. So my advice would be to do it once and do it right. If you can source some CO2 then you're laughing really. The ODL regulator as seen in the Malt Miller starter kit is really good by the way!