How long will it take you to make that potholder? If you spend a dollar on supplies, and it takes you an hour to make it, you are only making $4 an hour. Minimum wage is a LOT higher than that! (It's $7.40 here in MI.)
It would take me longer than an hour to make a potholder, but I am not overly fast.
Can you get a job at a local quilt store or fabric store instead? That way you will at least get minimum wage and also a discount!