Looks like this would work for any loads I'll see in my truck outside of the winch or battery connections, and the temperature rating will keep it happy anywhere except an obvious hot spot. I doubt I'll beat a $1/foot by much, and then I'd run the chance of getting a questionable product.
http://www.genuinedealz.com/10-awg-gauge-2-conductor-marine-wire-duplex-flat
See how many small, tinned strands in that cable? That's what you are looking for with quality cable. If it doesn't look like that, don't use it.