Let's round and call it $3 billion per month.
Roughly 130 MB for one hour of video (Assuming 360p)
130 MB = 0.127 GB
6 billion hours of video viewed per month
6 billion hours * .127 GB / hour = 762,000,000 GB per month
You can transfer roughly 320 GB in a month on a 1 Mbps circuit.
762,000,000 gigs per month / 320 gigs per 1Mbps circuit = 2,381,250 Mbps circuit
2,381,250 * $1,200 per Mbps.
This calculation is possibly wrong and provided for entertainment purposes only. :)