Ask HN: Best way to get a land line for my kids?

As we start the new school year, I want to add a "land line" to my house so I can tell them "devices are off at 8:30! If you urgently need to make a call, go ahead and use this land line."

I am hopeful this will mean they don't "just need to text someone" and then get sucked into the void of their smart phone addictions until all hours of the night, damaging their fragile sleep patterns.

Of course, I don't really want a land line. I want a SIP phone that connects via Plivo or Twilio. I've been looking on eBay and others to find an inexpensive cordless version that I can easily connect to Plivo.

I'm confused, however, what the difference is between a SIP phone, a DECT phone, Bluetooth and a WiFi phone, and if those can all be used with Plivo/Twilio.

For example this link:

https://www.voipsupply.com/voip-phones/cordless

Anyone have suggestions on going down this path? Do I need to run a PBX on one of my machines?

I figure the least expensive way is just direct to Plivo. The pay-as-you-go plan seems to be about $0.005 a minute inbound, $0.01 a minute outbound. That's easily worth my sanity.

https://www.plivo.com/pricing/