Re: AVG off 11.4 GB/month shows caps not out of line
Although you wouldn't pay more for the same car, you would pay considerably more for wear && tear, usage, gas and insurance if you choose to use it (or the service) more often.
Network gear && pipes are subject to wear and tear, maintenance costs and insurance I would suspect.
I don't think its out of line to charge more for the high-end bandwidth users.