Gonna get busier on here now Tony, gonna need a donate button mate! 
I'd rather stab myself in the eye with a rusty fork!
In all seriousness, in the past the agreement with BE has been that anything less than 100Gb/month is not going to be a problem, so in theory we're good even if we go a way over the level of bandwidth VOD has seen. Before hosting biopowered, this server did a fair bit of grunt work for a free open-source game community, and used to shift ~60Gb/month. At the moment we're seeing about 3Gb/month.
In practise, BE is in the process of being absorbed by Sky, so who knows how the T&Cs will change.
If bandwidth becomes an issue, then we'll have an open discussion about choosing a web host and how to finance it. No reason not to hop between hosts - we've already moved server machines and static IP address which is the same level of hassle, and that went well enough.
But, this place is a slim operation - everything is streamlined and there is a nice SPI firewall between the server and t'internet complete with flood and portscan protection, I think with the same number of users as VOD the bandwidth would be a fraction of VODs anyway. I'll be very surprised if we need to consider a paid-for web host.
The only argument I can see in the favour of going for a "proper" host is responsiveness of the forum, as at the moment the server only has a 1.3mbps uplink.