I'd reccommend against HD or Lowes -> they're too expensive.
try http://www.tigerdirect.com or http://www.newegg.com for the rolls of cable. Last time I looked one of them had 500' for like $25 or @30 incl. shipping...
-Dan
Builder of Bowser steam! Railimages Site
What do you use to connect the tortoise(s) to your control panel? I am considering 8 conductor cable for neatness but it IS expensive these days.
73
Bruce in the Peg