A Primary Refiner is a company that does the actual metallurgical processing to extract and refine the Platinum. This does not mean that they can provide better pricing. Here is why- Refining Platinum is extremely difficult, and these large companies have expensive technical equipment, a large staff with a sales team, and their fees must support the company.
Almost all of the businesses that do platinum recovery for EP Labs are not Primary Refiners. They often say they are, but it is a deception. This is true for the best known company, and the guys that travel around with a scale (much of this weight is plastic, so it is just a show). These companies may do some processing of the catheters, but then they send them off to another company to do the actual refining.