Some info for fellow ExtraBucks junkies.
Be careful. I've learned that during transactions for which you have numerous various coupons to use in conjunction with ExtraBucks, the cash register or cashier--haven't yet been able to determine the culprit--sometimes applies the ExtraBucks before all coupons have been applied. I've been burned for $3 here, $7.50 there; it adds up. For moving forward I have vowed not to hand over my ExtraBucks (essentially the equivalent of cash) until I'm certain all coupons have been applied, even at risk of eye rolls from a certain usually-not-pleasant manager!
Happy savings...