@serenesurface-- There are different types of moon cakes, some being more sweet than others. But what they all share in common is that they are made with lots of butter so they are very rich. The reason that people buy a few is because one can't eat a lot of this delicacy. Traditionally, a single moon cake is cut into four quarters for a family of four. So every gets a small piece. But believe me, that is enough.
If there are Chinese groceries in you area, you can definitely find moon cakes at the stores. Most people in China these days buy them commercially too because it does take some time to make them. All this talk of moon cakes has made me crave some! I can't wait for the moon festival now.