Haha i would of thought it would have been easy for people in us, you don't need to worry about making sure you dont use all your bandwidth, but still trying to sell enough servers to make $$$. (im australian if you don't no).
If i was going to start a US GSP, i would Buy my own hardware (
http://www.newegg.com) <- wish we had some of that
then i would find a host who i can get unmeatred bandwidth plan from someone like
http://directspace.net/colocation.htm (dunno if there good or not, just saw they can sell dedicated bandwidth @ $10 per mbit).
I would buy 10mbit's for $100 + $50 for rack space.
Charge 99c per slot, then put a max of 300 slots on it.
(overselling a bit, but very unlikely you will ever max out the connection).
There you go, $150 profit per box, now you can go buy 150 taco's from tacobill (they where a $1 when i went over there 11 years ago
).
Chris