didx.org offers wholesale only did numbers and peering service solutions for ITSPs. The per DID rate is set by the DID owner and thus varies. US DID’s average at about $4.50 per month with 5000 included incoming minutes. The best part about this service is the fact that they have a working api. Here is my code for using their api, based on their examples.
1) getdids.pl
This small perl program basically takes two arguments, country code + area code, and returns available DID’s that match that pattern. To view all DID’s availabe for a certain country code simply pass -1 as the area code. Make sure you replace the user and password variables with your username and password.
This program takes one argument, the did that you want to order, and returns all associated costs. Again make sure you replace the authentication variables.