It's exactly the same model used by fitness clubs worldwide. And Comcast cable Internet, Google Fiber, every DSL provider, even every cellular data provider.

Current true bandwidth costs about $0.50 (50 USD cents) per Mbps, per month, sometimes even less.

Average 1 month usage of a 1Mbps link that has Internet traffic on it is about 175-210GBytes.

Literally less than 1/3rd of 1 penny, per GB of data.