> Really? Your costs are as low as that?
Uhh, yeah, and I know I'm overpaying too (though its just $20 or so). VOIP is a solved problem in the US if you avoid resellers like Twilio, Nexmo, etc and go directly to either a CLEC or a voice wholesaler.
> Who are you using for your provider?
Endstream (NPA-NXX) & Bulk Solutions (Flat rate @ $0.0045/min), but there are cheaper providers out there if you spend a few hours and set up Freeswitch to do LCR.
We bring in another CLEC for our DIDs (though we have a few dozen with em), SMS/MMS & E911 due to price & convenience, Endstream is still shaping up their offerings in the SMS/MMS arena.