If anyone is interested in this still.
I've got a price plan up for anyone who wants to lease a server from me.
http://hosting.azmod...products_id=180
The cheapest plan there, is about $12.50 per month + Usage Costs.
On Usage Costs: This will include $0.10 per 1 million Disc I/O operations. The people demo'ing this for me, who have had their server up online for 82 hours so far, have only accrued 8 cents of I/O Charges.
It makes sense financially to charge based on usage, since there is no logical reason to pay a flat rate for a server that no one is currently playing.
So if your sever is not getting any players, then that time is charged at a cheaper rate, than when it is really busy.