I'm the one with the "average" tub of scraps. I didn't say it well.....I have a tupperware tub of average size worth of scraps. I don't know what a normal amount of scraps is either. That's like asking what a normal size stash is I think.
I want to try postcards too. I'm thinking of adapting some papercraft cards to fabric for that purpose. There are some great homemade card ideas out there.