As a matter of fact, I tend to disagree. Hubhosting requires much more upstream than downstream traffic width. The downstream of a 300 user HeXHub is as follows:
Received: 71 bps (0.071 kbps)
That means around 72 Bits per second, also known as 12 bytes per second. This is almost nothing compared to the upstream which is:
Sent: 395 bps (0.395 kbps)
Please take note that this is a HeXHub, not a YnHub, so that is why the bandwidth stats look a little "wow"-ish in efficiency. In the case of YnHub which is more commonly used, you would need even more upstream and still use roughly the same downstream.
My point here is that only upstream really needs to be limited when running a hub. And if you wanna know a little secret, always make sure you are downloading at the most of 10 kbps lower than your max capacity, because you still need a little downstream to keep the hub's influx of commands running smoothly. How's that for an evening lecture?