hm the prob is: theres no such flatrates for servers.
i mean sure there is flatrates. but much more expensive.
on the market for private people they can do such cause the mentioned reasons.
the drive of the server wont get full, nothing could stop me from blasting out 400 TB (400000 GB) with an asrock onboard NIC every month...
btw: the internet itself is basically free. you can have peerings, np:
http://decix.de/content/services/public-peering.htmlits neither pay nor flatrate. its being the internet.
btw, u need some a bit more money for 1-2-3 compis and membership in ripe etc. but thats then it, no big investions. all in all far less then a new mercedes or a toilet of platin.
some "free spare time" should be a good idea.