300mbit connection - max theoretical bandwidth usage is: (((300/8) * 60 * 60 * 24 * 365)/12)/(1024^2) = ~94GB. This guy did pretty good work!
Soulver tells me: 300 megabits/second at 30 days in terabytes is 97.2 terabytes. If you have a Macintosh - get Soulver. Just doing bandwidth calculations alone makes it worth it. Thank you Marco Arment for telling me about this wonderful app.
Soulver: 300 megabits/second at 30 days in terabytes is 97.2 terabytes
My calculator: 300,000,000 * 60 * 60 * 24 * 30 / 8 = 97,200,000,000,000 bytes.
Soulver wins.
Note - in everything (Storage, Bandwidth, etc..) except memory, megabits means 10^6, not 2^20. One day, perhaps mebibits will catch on...
(Google: 300 (mebibits / second) = 94.0469681 terabytes / month