Technically you can run gigabit on cat 5 it's just not rated for it.
HA I can buy 5 of these for a 10th of the price of a 500ft box.
http://www.amazon.com/100FT-PATCH-ET.../dp/B001AVZFDA
I might do that cause i'm sure i won't be running any longer than 100foot runs i could just cut the ends off.