Richer?
I think you need to check your maths...
If 80% will pay no more that current cost then that brings in 80% of current revenue.
Move the price to double and you get current revenue - 40% who are willing to pay this price and 10% who would pay even more. 50% * 2 = 100%
Finally at triple current cost, the revenue would be just 30% of current.
Your 5.1bn assumes that people would pay different tariffs just because they think the service is worth that much but who is going to pay double or treble if the cheaper tariff is on offer?
Biting the hand that feeds IT
