Back when DTMF dialing was a newly introduced technology, Bell Canada in Ontario, where I was a student, had three different rates for basic service: the incumbent rate for existing pulse dial phones with a dial, a higher rate for new-fangled DTMF phones with a keypad, and a higher rate still for hybrid pulse dial phones with a keypad.
It hadn't been all that long that the consumer could buy their own phone from the local discount mart. If your phone generated DTMF phones, it wouldn't work without paying Bell more money for the "advanced" service. But you could buy a phone with a small micro-controller where you dialed with a keypad, but it pulse dialed over the line to impersonate the old phone you used to have. Usually there was a small slide switch on the bottom to select the dial mode. Of course, DTMF completed the dialing a little faster than the pulse setting.
Bell had no way of knowing that you had a keypad phone generating pulse dialing on the line, but if you allowed their technician into the house and they caught you with such a phone, they would convert you to the highest basic service rate of all. It was like another $5/month, which for a student, was super annoying.
Bell PHB: this is new fangled so we have to charge more, but it saves us money to deliver the service by allowing us to retire the old and slow and decrepit line cards, so we need to promote moving people to the new technology as fast as our bean counters can waggle their abaci, while also simultaneously incentivizing the change-over with higher fees.
If I made 50 calls per month at 4 bytes per call, it worked out to something like $5 / 0.2 KB or $25,000 / MB.
Russ Roberts has been trying to sell me on the Hayekian virtues of the private sector for about 150 episodes now. But I remember Bell Canada, and I know the private sector will charge you more for the benefit of saving them money at the drop of a pin, if they can get away with it.
Oh, yes, the solution is to deregulate. I got the memo. That's why I'm presently so much in love with my cellphone service, and I bet you are too.