USA/Canada trades for about USD 0.01 (one cent) per minute if you buy in
large volumes.
For about $4500 per month you can lease a T1 in USA at a flat rate.
It means, send as many calls through those 24 ports, as possible.
In some cases a number may not be available for a certain location. But usually it's not a problem.
All the info you need is available in the website above. Click on the link for the phone you're interested in & query their details for what you're looking for.
If you are looking for simple voip solution then you have to trust me.
I have used many in the past but the one I can recommend to others is Voipography with their PBX on the cloud, Your visitors are in direct connection by click2dial, Your dynamic auto attendant in your hand, your whole sale voice termination, and your secured voice telephony , all in one platform, absolutely the best .
You can check them at www.voipography.com info@voipography.com