Hello,
I first would like to say that I've been following this forum for about a year, but never registered, or posted until today. I own a new edge cougar and mainly post over at fastcougars.
To raise money, I can think of several things that do not result in membership fees. Why not simply raffle items off, and use the proceeds from those raffles to help pay for the server hosting costs. The cougar forums have done this for quite a while now, it even helped pay for the server, IIRC. Basically, FastCougar offers up a banner to the company in exchange for a product to raffle off. He obtains the part for reduced cost or free.
If you are interested in lowering the amount of bandwith, I would suggest removing some of the images from your pages, especially the forums, such as the cougar logo at the top of this page. Also, instead of having button pictures in the replies, why not just have text options. Images use up the majority of bandwidth.
Anyways, I think that these options are much more realistic, and while providing money to help run the site, it also provides a service and something enjoyable to the entire site.
Some items that have been raffled off at the fastcougar forums include: rims, spoilers, body kits, Intakes, and exhausts.
Paul