The other site I'm a major(?) member of is going through this same issue. The site owner finally admitted to having some issues with keeping up financially (why do the good owners always seem to do that?)
Luckily for that club, we have a few members that have designed, and sold, promotional merchandise (T shirts, hats, decals, etc). The staff over there finally talked the owner into accepting a $1 surcharge on each item sold, to go to site maintenance. He still won't let us just donate, though.
I bring this up because it is a fund-raising method that is self recurring. Every time someone buys a piece of merchandise, a donation is generated. While it may be a bit more difficult to implement that plan here, something similar could work better than hoping members remember to donate every so often.
Ideas I've had are a CafePress store, designers donating original models to a site store, or see if some of the more popular vendors would be willing to implement an affiliate program.
Just tossing out experiences and ideas.....