If 700 members all donate £1 quid. That's almost double the goal. Personally i'm not interested in the sticker / join up stuff. You've gotta pay to have that shit designed, then it looks crap still usually and they wind up in the bin. This forum is great, and i'll head over and donate after finishing typing this post. The forum has saved me a fortune not only with free advice but also with buying and selling with no fees. We'd all be raped for more than a quid every time we sold something on ebay so I really think it's more a moral obligation for us all to put something in really.
If it was my site i'd just do a £5 quid a year maintenance cost. £5 is less-than-fdoc-all in anyone's book and I really don't see how anyone would have a problem with that. At any rate, if people are too tight to spend a fiver a year in order to save £100's maybe £1000's on free advice and good deals on parts and saving on selling fees, who wants them on the site anyway.
Just my 2p worth (I'll probably donate more than that, unlike Sacrilegious)