My cost on butts is $1.41lb 50% yield means I have $2.82 in the meat cooked. I sell at $11.50lb but would probably sell to someone who will be buying at that interval for $9.00lb deduct my cost of meat because he is supplying it (provided he is a licensed supplier through his store and handling properly) I'd sell it to him at $6.18lb and shave as much as another $1 off of that if the relationship was working good. As far as ribs go I would not cut a deal as they don't make enough profit anyways. I'd probably do the ribs for $10-$12 per rack if he supplies them.
For me this would be provided he was not wanting it on Saturdays when I can make more money catering and it would interfere with that. Also I would stipulate that he could not advertise it was cooked by me because you don't know how he will handle the product, ie let it dry out and not be good and people think that is how your stuff tastes.