> Source?

http://amazon.com/ip-transit

Just kidding. Seriously though, you are not going to see wholesale rates posted on a website. Contact your bandwidth provider and ask for a quote. For serious volumes and good pricing, expect to sign an NDA.

However, to give you an idea of lowend pricing here are some examples from FDCservers. This is not an endorsement, just a site with easily accessible prices that I could remember off the top of my head. In fact, I emphatically do not recommend them. There are much better providers both in terms of price and quality.

Remember 0.1 cents per GB equals about $0.30 per Mbps.

Asymmetrical 100G at $0.15 per Mbps https://fdcservers.net/ip-transit.php

Metered 10G at $0.60 per Mbps https://fdcservers.net/colocation.php

Unmetered 10G including server $500 https://fdcservers.net/dedicated-servers.php

$0.003/GB is what $1/1Mbps is, at 100% utilization. 324GB is what 1Mbps can do in a month. Perhaps a bit less but low quality providers (HE, Cogent) will do a dollar a Mbps easily. So work backwards. (Another way, you need 3kbps to do 1GB in a month. That times 333 is about 1Mbps, so $1. I'm ignoring 95th percentile billing here.)

Better providers like L3 are around $3/Mbps, last I heard.

So $0.001 a GB means you'd only pay 33 cents per Mbps, which seems pretty low. But maybe at terabit commits, HE goes even lower.. I've only looked at 10G commits.