would be a lot more useful if second non-data lines were cheaper.
You want cheaper than $8/mo for unlimited talk/text and no data (U.S. Mobile and Tello)?
Every now and again, Tracfone will run a special through their eBay store for 360 days (not 365 days) of service for unlimited talk/text for
$100 -- choice of AT&T, Verizon, or T-Mobile network.
If you don't need unlimited talk/text, then there are even less expensive plans such as the recent (but expired) offer for 1200 minutes talk / 1200 text for 1 year prepaid plan for
$24, or customize a plan from Tello (300 minutes talk / unlimited text / no data is $6/mo) or U.S. Mobile
There's also Red Pocket (T-Mobile MVNO) on eBay. You can get a 1 year plan that gives you 200 minutes talk / 1000 text per / 200 MB data per month for
$30 (works out to $2.50/mo)
None of this applies if you're outside the U.S. though. But if you're not, cheap no data plans do exist.