Greedy children appear to concern a lot of people this time of year. It seems like everyone has a child with the "gimmes" especially during the holidays. In fact my daughter and I caught a segment where a "parenting expert" was counciling parents how to "cure" their children. Her main advice was for parents to tell their children it was a recession and they couldn't afford much.
My daughter snorted, "Then they'll just wait until the economy is better and expect double presents!" She is right. There are a lot of ways to help your child take the focus off of what they can get, but giving them partial or incorrect information is not the best plan. Our daughter is incredibly responsible with money and always has a very reasonable and short "wish list". In fact, until recently, she rarely had more than two or three items on her entire Christmas list.