I'll drop some over after pay day David, things are pip squeakingly tight right now.
Hosting for a forum of this size should cost around £4 - £10 a month, I was up to over 1000 members before I had to upgrade to the £10 option. I'm currently paying £40 a month now the membership is up to 3000 with 100+ active members online at any given time, this cost is covered by a couple of adverts. I must admit I've wondered about the need for running my own server like Turbo minis does but the costs don't add up for me and my forum is busier than TM.