Hosting is on a $20/month Linode along with a bunch of other projects/sites/bits of code fluff. The actual bandwidth used by this site will be virtually nothing I imagine. I haven't valued my time at all. In that respect it is already earning me around $40 a month - a meal out.
Are you paying any money to the original author?
He's not bothered - it's an experiment for both of us. If it works out then I'll see him right, but there's no point in hashing out some lengthy agreement if it doesn't bring in the bucks.