Money as a Means of Discipline

Question:

How do you feel about using money as a means of disciplining children? My ex-wife has developed a system of “Stars and De-merits” with our children—6 and 8 yrs old. They are awarded for good behavior with stars or dollars, and when misbehaving they receive demerits and money is taken away. She feels that this system allows her to adequately control the kids but I feel that our kids are becoming obsessed with money and expect rewards/money for everything they do. I am afraid that this system is teaching my kids poor values, my wife disagrees. Please help. Thank you for your input. Jack