This is the same kind of cable I just purchased.... $.41 cents a foot here:
http://www.markertek.com/MTStore/product.CFM?BaseItem=4S8
It's 2 sets of twisted 16 guage wire - supposed to be the equivalent of a single 13 guage wire. Twisting wires helps with external signal rejection. Add your own connectors or leave them bare... and the price isn't significantly more than zip cord.
There's a fatter cable, too - the 4s11 which is 4x14 guage wire, 11 gauge equivalent. I'm only planning on running about 20 feet, so that's overkill for me, really.
