I get discounts at Midway, Midsouth, MidStates Cast Bullets, Sarco, Numrich, Brownells and even a couple finishing vendors for parkerizing, bluing, case color harding and browning. There is always Century, Hunters Lodge and Kambe Keep. Lee Precision and RCBS will discount die sets for "C&R" calibers.
I am sure there are many others. The discounts range from 5% to 35%, some of the orders for bullets for reloading really add up for the discounts. I have probably saved close to $285 this year just on .38spl bullets. That was enough to pay for tangible Powder and Primers.