I've lost track: maybe you have an old plan that is no longer available. What I see on the T-Mobile Web site is a limited-time offer of a $20/mo. tablet-specific *add-on to an existing voice plan*.
Our current two phones on the only postpaid T-Mobile plan I see on their Web site would cost $120/mo., including far more data than I can imagine us ever using. The cheapest prepaid family plan would cost $80/mo., including more than twice as much data as we are currently using. Our Project Fi service is costing less than $60/mo. because we get rebates/credits for the data we don't use.
And yes, an *extra* 1GB even on some expensive Verizon plans that already include data is less than the $10 each 1GB costs on Project Fi. But what is the *total* cost? How much is one already paying for the first xGB of data with Verizon before one gets those extra GB for less than $10/mo. each? (And the last time I checked out Verizon plans, I saw that each smart phone incurred an extra $20/mo. charge on top of the other charges.)
And I have already agreed that Project Fi is not advantageous for everyone -- not even if comparing new plans rather than including old "grandfathered" plans -- especially if you have people using a lot of data. E.g., there is no built-in overall cap and no slow-down after xGB: if you had a teenager using multiple GB of data, you could end up with a huge bill. But there *may be* Project Fi group plans in the works with a "rationing" feature.
Perce