We here in Australia have been subject to tiered broadband pricing since day 1 - I feel pretty comfortable in saying that whatever pricing US carriers come up with, it will be much lower than here in AU, simply because you don't need to haul most of your data thousands of KMs via undersea cables. My ISP has a range of ADSL2+ plans from AU$50/month for 150GB data through to AU$120/month for 1TB data. (There's also an entry level 30Gb for $30 plan for your grandparents)