Paying for top grade rice

There was this restaurant that used to buy low grade rice. Over the years, as its business improved, it increased its budget for rice. Gradually it moved from low grade to medium grade, to top grade and to the best grade money could buy. It's budget for rice increased from $200 monthly to $2000. All was well and they kept telling their guests that the restaurant served the best grade rice in town. The bosses were happy, the customers were also happy. The most happy person was the master chef. He did all the purchasing. What the bosses and the customers did not know was that they were paying top dollars for the same low grade rice all the years. No one was wiser except the master chef.