$40 per month for an Atom based server (which is surprisingly capable). They have an advertised traffic quota, but in my experience they don't check how much traffic you've used. I used to run a file host on boxes from Interserver - I used to push about 60TB per month over 3 boxes.

One thing to check is that some of the budget hosts will oversell their networking in such a way where your port links at one speed, but you're unlikely to ever see that speed for long periods of time.