not much. looking at my router for banwidth monitoring:
LAN: 22kbps IN / 25kbps OUT
WAN: 10/12
Wifi: 20/22

This is between 6 antminers, a bitfury, my laptop, and a 2MH/s scrypt rig.   Its safe to say that the bandwidth usage is next-to-nothing

for renting a co-location, you need the slowest option they have. you could probably get away with dial-up. (This is the reason i opted away from the co-location route; datacenters are designed for FAST internet and moderate power demand. Bitcoin miners only need a basic internet connection but HIGH power demand)