The thing about spice is the shelf life,don't buy more than you will use in 6 mos to get best results. You can get a great but on quanity sometimes but if it'snot going to get used it's no bargin. Store out of sunlight, dry, cool spot.
I have a spice wholesaler within a few miles of my home, but the quanties are on large size so I get a couple of friends together and we split it up between us.
This company makes up rub for me in 15 to 25 pound batches but because of cooking classes and charity cooks I can go through that weight in 3 to 6 months.
For competitions I still will make up batches at home to insure the freshest product for that cook.
Jim