You can go to a metal refinery such as Hoover and Strong in Richmond, VA or you can go to a jewelry supply store to purchase specialized findings. In your city, if it is large enough, there will be a place where the custom gold smiths and jewelry man...
What I know is that the rules have been changed recently, and all matches will be 3 sets exept for men's Grand Slams (5 sets). So now the masters series final should be only 3 sets.
It would depend on how much your overhead and inventory cost. You DO NOT truly make a profit until all of your inventory, overhead & other business essentials are paid in full.