You'd almost have to find like-minded people (mostly Catholics) who are interested in not being wasteful, and have an interest in becoming more independent from "the system".
Usually when you grow vegetables, fruits, etc. you have WAY more than you need -- wouldn't it be great if I could grow a bunch of cantaloupes and trade them for things I didn't bother growing? That would be a win-win for everyone concerned.
Same goes for seeds -- I'll give you some of my extra seeds, and you give me some of your extra, so we can both plant more than we spent money on. Usually seeds are cheaper in bulk anyhow.
Especially if you want to try to dry your own seeds from fruits you grow (assuming the fruits were grown from organic or "heirloom" seeds), it can be a bit of work. But if you only have to do 1/3 of them, because 2 other families are participating, it would be so much better.
Matthew