Hi Ray,
I have also given this some thought. I reckon you need to keep the site going for longer and bear the cost at least until expo next year. Think of it as an airline that enters a market on a route that is marginal but will become successful given time. You need to build the trust of the punters which will require investment and patience. Maybe draw up a graph that shows members joining versus time and see what the curve looks like. Is it exponential growth? was it high to begin with and then has tapered off? Has it grown slowly over time? These points may help to see where the site is membership/cost wise in 6 months or even a years time.
I think there would be a good case to get some shirts printed up that members could wear, especially at events such as Expo next year. Think of our members wearing ACAM shirts who may be up `on stage' accepting awards and the like and the attention this may bring. There would certainly be a business case for getting the shirts, as there should be a mark up over your cost which would help offset the cost of the site. Say a shirt costs you $20 per unit and then members could buy them for $40. 20 shirts = $400 that could be used to pay for the site. I think your core members would be more than willing to do this for you.
I have seen guys happily blow a couple of weeks wages on models at a show but then be missing in action when it comes time to pay for club membership fees. I guess that is the stingy nature of modelling in general but I reckon you could offset the cost of the site by using such means as outlined above by me, and advertising as outlined by the others.
Eric.