If people wish to sell here / advertise then membership is required.
You stated, you would be making no financial profit from the group buy, however you did not mention who the company was and pretty vague on the details.
Do you seriously think members here would pay out £950 with a week's notice and not have any idea who they are paying there money to, I'm not doubting your trust worthy...........but you see my point.
As long as the MSC is a car club, which it will continue to do so, then Membership will remain in place. The best value for money package is just £10 per year, hardly a massive contribution to ask for!
Kev