If you're a business that relies on high-performance from apps that run across a portion of the public Internet, it makes complete sense that you would want to be able to pay for higher bandwidth and a higher quality of service.
You can do that now, with no trouble. Don't even call your carrier. Just whisper somewhere near a networked node that you want to buy a new service plan and your phone will start to ring with calls from customer-service and sales reps.
There's no reason to let carriers or other vendors put you in a position in which the charges are supposed to change with your level of use, then sign on for a plan whose costs have a solid floor, no ceiling, and automated ways to ratchet themselves up without your even having to know.
"Tiered pricing" sounds pretty reasonable when you think about the amount of development you'd have to do to build similar networks, the level of service you want and the extremely small window of opportunity you might have to make a networked project work.
Paying a little more to get a remote-hosted desktop virtualization project off the ground might be worth it.
It isn't; not if Google and Verizon and Comcast and Time Warner get to decide what the minimum costs are that you'd pay, and squeeze you every time you go above whatever minimum levels of service they set.
And remember, over time, "minimum" levels of service tend to decline because they're the minimum. If the service you get now is good for the amount you spend, that's great. In two years, that ratio may have changed radically and you won't be able to do a thing about it.