As an extension to this comment, other costs that could impact the delivery price of 1GB of total usage:

- speed

- overall saturation of tower (# users per tower)

- population density (full coverage of an area may be difficult)

- technology; https://en.wikipedia.org/wiki/Comparison_of_mobile_phone_sta... which could affect federal regulatory licensing costs, technology licensing and acquisition costs and competitiveness of market to provide technology, tower density, total user capacity

This is my laymen's interpretation. For instance, to blanket the US (9.834 million km² and 36 people per Km2) in LTE would be a significantly harder challenge then blanketing Myanmar (676,575 km² and 83 people per Km2) or even Norway (385,203 km² and 15 people per Km2).

Just look at the stats for Myanmar, 86 people per Km2, and I might be able to get most of them within 300-500k km2. My subscriber base is excellent!