That would depend on how you have your customer database set up. They are wanting to become one of your customers, right? Then, I would determine where in my customer database they would best fit.
1. Full retail customer
2. Full retail customer, free pickup and delivery
3. Commercial account, afforded some sliding discount that is given according to volume sales
4. Wholesale account, given the standard discount that my other wholesale accounts get
5. Whatever other breakdown you have for charging your customers
This is simply an example of what I would consider if they approached me for framing. I would NOT give them any blue light specials nor would I cut any deals on them buying all the materials and me doing all the labor, .......... things like that have a way of coming back to haunt you.
Are you expected to set up their retail pricing for moulding and matboard and all the other incidentals like glass and fillets? You will have to coordinate with them how much they should charge their customers so you get your fair share. Another way to charge them is for them to call you for an estimate in advance, they tack on whater up-charge they might feel they need from their customer, and then they would contact their customer to finalize the order.
If they become efficient at writing framing orders, I see no reason not to afford them some kind of discount for doing all the leg work for you. That could turn out to be a sweet deal for you if you lay it out correctly and put some thought into how it will work after their framing volume builds.
Good luck.
Framerguy