If it is a large local mailing then yea we truck to the SCF and charge accordingly, otherwise we drop at our local BMEU. Just because your taking it to the SCF doesn't mean you will get SCF discounts unless that mail is all local. I run distribution reports to see if it is worth it to either drop ship or deliver to SCF's. Then the customer gets the postage discounts and we charge a service charge for delivery if it is worth it for both of us.
Sometimes SCF delivery isn't about discounts but about speed of delivery, so you have to factor that as well.