I have a unlimited Data plan on my GSM Galaxy Nexus in the UK I do not have DSL at home and use my Nexus as a hotspot for my Laptop's and my Xbox 360 and Netflix. I use about 60GB to 80GB Per Month. How much Data do you use on your Galaxy Nexus ?
About 1.5-2GB. My typical day involves me being in the basement of a building with no service whatsoever, so it'll be in airplane mode. Evenings and the weekends are the majority of my usage.
This phone uses more data than my HTC Desire although, not enough to reach Orange's Fair Usage Policy of around 750mb. Last month I used 700mb, this is just surfing and general uploading and downloading files, no tethering.
I use only about 2-3GB per Month, but always attach to the work and home wireless to save on the 3G bandwidth and battery. Including Wireless use, I would guess I'm up in the 20-30GB range, only Email, Twitter and G+ use much 3G.