We do a group order that we set up ourselves through Disney. I want to say we saved about $10a ticket? A 1 day pass (not park hopper) was around $70 if I remember correctly
This is from the website -
Disneyland Park and Disney California Adventure Park offer discounts for groups of 15 or more from qualified non-profit organizations. For detailed information, prices and tickets, please call (714) 781-4565.
We aren't non-profit so I don't know if we went through something else but we had a special website link set up just for us to order our tickets through