I'm not sure if you can get a 100 Mbps link for $45/mth, but you definitely can get a 1000Mbps link for $450.
Transit is so cheap these days that it's almost free; it's very cheap, keeps getting cheaper, while many other costs are not getting any cheaper (electricity prices don't ever seem to go down, for example). As a result, transit seems to be making up a smaller and smaller percentage of costs.
I agree with you on the general principle involved here (and the pricing scheme being discussed here is nonsensical), but transit is only that cheap at major junctions. When you get farther away, it gets much more expensive. Additionally, in rural areas, fewer customers have to support cost of the backhaul infrastructure to make it out that far (and trying to economize .
It gets expensive for rural customers on both levels.