Another thing to keep in mind is that MVNOs provide service at cheaper rates because their customers are generally not provided the same high speeds that the network owners (ATT, VZ, TMO) provide to their direct customers, and the MVNO customers are the first ones to be throttled if the network gets congested.
In my experience with Spectrum Mobile ($45/mo for ‘unlimited’ service), which uses the VZ network, the speeds are more than sufficient for my needs. And if you don’t use a lot of data, they have a plan that provides data by the gigabyte, for $15/mo per gigabyte. So if you generally use less than 2 GB of data per month, you’ll pay less than $45.
Oh…‘unlimited’ data is really 20GB in a month. After that, they throttle your data speed to 3G, making it essential unusable for the rest of the month. I never use that much data in a month, so it never affects me.
To get those mobile rates, you need to be a Spectrum TV or Internet customer. And there is no contract with them.
I also bought data service for an iPad that I have, from a newer company called Tello. Their rates are very low, and they have a wide variety of plans available, so you can build one to suit your needs. And no contract is required; it’s a month to month service.
https://tello.com/
-rb