Determining Prices for a Craft Fair?

Please help. I would like to sell my handmade patchwork tote bags (made out of old jeans and new fabric) at a local farmer's market this summer, but I don't know how much to charge. I know how much the jeans and fabric cost, but I don't know how much to charge for labor, thread, use of my machine, etc. I would also need to invest in a canopy and tables for my booth. The bags are an easy technique, but it takes 2-3 days to make a bag, if I don't have any other wife/mom things to do.

Plus, I live in a community with a lot of crafters who could make the items they see at a craft fair and people who like to negotiate for a good price. Thus, I need to find a fair price that will not scare away potential buyers, but will give me room to negotiate and still make a decent profit. How do I make my craft fair dreams happen?

By Marie Lindholm Van O. from Idaho Falls, ID