Can't really help you there as I always buy hardware at a store. It also depends where you are. UK has some cheap sites IIRC, but one of the cheapest I ever saw was an Eastern Euro online retailer, can't remember the name. If I do I'll post again.
Sapi back in 2003 when I was really hardcore, 10GB a month was gone in a breeze on 512K, then I upgraded to 1MBit.
Now I'm on 10 MBit (though it's shared), and I only do about 3-5 GiGs a month. Much more this month as M2TW has made me do all kinds of research. Watching videos (youtube etc) on all kinds of history. Gaming can take up a lot of bandwidth unknowingly. Also SKYPE can use a lot when you use it as a primary phone and you're almost always on.
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