We just about always give our customers what is left of the paint we used on their cars for free, and we occasionally mix up custom touch ups for anyone who walks in. I would rethink the idea of not going to a body shop, as they can usually show you a color chip of the paint you will get and if there are any variances for the color for your car they can pick them out right there. We usually charge $5 to $10 for a touch up bottle.