Why championship chess sets are so expensive

An inexpensive chess set can sell for $20, but a handcrafted wooden set certified for the World Chess Championship costs $500. Much of the set's value lies in just one piece: the knight. Each knight must be carved by hand to look exactly the same. Making this one piece takes two hours, and there are fewer than 10 people trained to carve knights for the championship chess sets. So, how are these chessmen made? And why are they so expensive?