I suppose this has been done before, but I can't see a thread so...
Considering how much it must cost to run RAWK have you considered some advertising content? A tasteful (small) banner advert for a RAWK approved product (or even to the official website perhaps) would hardly be noticed by the bulk of posters, take advantage of the huge numbers of posters, help fund the costs of the site, future proof it to some degree and possibly even reward those involved.
What I have seen elsewhere that I thought was good was an Amazon referral link. Anyone wanting to buy something on Amazon clicked through to the site through the referral link and the host was rewarded for their successful advertising. It was worthwhile because it allowed the purchaser express his/her thanks without any real cost to themselves.
Amazon has a great affiliate program. You can pick the item or items you want to promote, and you make a 4% commission for referring that customer to the Amazon site. The other cool thing about Amazon is if the person you referred to the site purchases additional items while they're on that site, you get the commissions on those as well.
You could also look at using something as simple as Google Adsense. I don't know how much traffic this site gets daily, but finding a way to integrate a simple Adsense banner on the page could generate the site somewhere in the ball park of £5-£10 per day.
Server costs are server costs, and every little bit would help.