Just the usual suspects, Powder valley, Bruno, Midway etc.., I don't think there is a special price for large quantity but I may be wrong. I bought mine over two years ago. What caliber?
Don't quote me on this but I think Lowlight and a few others have posted some promo codes in the forums here for Midway and I think they usually have the brass in stock, just look around and if you find the codes try an order and put in the different codes till one works. I'll try to find the thread and let you know if I find it. Who know's maybe you'll save a few bucks.