I'm a little confused with the word THEY in (So they improved the product and lowered the price). Does it refer to the buyers or another company which is Costco's competitor?
In 1996 we (COSTCO) were selling between $150,000 and $200,000 worth of salmon fillet every week at $5.99 a pound. Then our buyers were able to get an improved product with belly fat, back fins, and collarbones removed, at a better price. As a result we reduced our retail price to $5.29. So they improved the product and lowered the price. The buyers weren’t finished with the improvements, though. Next our buyers negotiated for a product with the pin bone out and all of the skin removed, and it was at an even better price, which enabled us to lower our price to $4.99 a pound. Then, because we had continued to grow and had increased our sales volume, we were able to buy direct from Canadian and Chilean farms, which resulted in an even lower price of $4.79 (Denning, 2005, p. 137).