I'm curious how much bandwidth you go through.

I only use OT so I'll sit it out for a month.

I would think it's better to work out where the bandwidth is coming from and deal with that. It can't be just the forum. I've got 7000 members on mine and only do 25Gb a month. The whole lot only costs me 50 quid a year.

If you have a lot of people leeching the image library it's better to block that and keep your own site accessible. Or find a better server deal with more bandwidth.