> In the case of AT&T, pricing can start at $55 per month for a 25Gbps plan before going up to $65 per month or more after a year, and the company will charge $10 for every extra 50GB you use (unless you upgrade to unlimited for $30 per month or have a plan that’s already unlimited).

The pricing can start at $55 per month for a 25Gbps plan is clearly a reference to the "Internet 25" plan which is 25Mbps (not Gbps) and has a 1.5TB cap. But I don't know why anyone would choose that plan unless it's all that is available at their address since the "Internet 50" and "Internet 100" plans are the same price and the "Internet 100" plan is unlimited.

All of the AT&T Fiber plans are also unlimited.

Pricing page:

https://www.att.com/internet/internet-service-plans/

There's a footnote on the price for the Internet 25, 50, and 100 plans indicating the data cap: "Incl. 1.5TB data/mo., overage charges apply." There's also "See offer details" link with this pop-up:

https://imgur.com/a/mZBetsA

It links to https://www.att.com/help/internet/usage/ for info on data allowances. Internet 25 and Internet 50 have the 1.5TB cap, but Internet 100 is unlimited.

It's weird that AT&T would price all three of these plans the same and apply a data cap only to the slower speed plans. I wonder if it indicates is more expensive for them to provide the lower tier plans for some reason?

Disclosure: I've had AT&T Gigabit Fiber since Jan 2017. It's $70/month (total) which has included HBO Max as a freebee for several years now. No data cap. It's the best residential Internet service I've ever had, by far.