The US operates a bill-and-keep [1] model for phone calls, which is why people pay to receive calls on their mobile phones, and why spam texts are more prevalent.
If a call is made from Verizon to AT&T, no money changes hands between them.
ISPs have typically operated a B&K model where the traffic is largely symmetrical between carriers. The argument arrives when the flows aren't symmetrical (such as streaming video).
As for Comcast paying to upgrade their network, there is precedent in the Cable TV model where they both pay for the content and pay to upgrade their network to receive, carry and bill it.
Networks derive value from the connections. If there was proper local competition then this would fix itself over the course of a contract cycle since a competitor would enter offering a network with a better value.
[1] http://en.wikipedia.org/wiki/Bill_and_keep