From the Kentucky Court of Appeals (via a friend on Facebook):
Beyond a certain point, additional child support serves no purpose but to provide extravagance and an unwarranted transfer of wealth. While to some degree children have a right to share in each parent’s standard of living, child support must be set in an amount which is reasonably and rationally related to the realistic needs of the children. This is sometimes referred to as the “Three Pony Rule.” That is, no child, no matter how wealthy the parents, needs to be provided more than three ponies.
Downing v. Downing, 45 S.W.3d 449, 456 (Ky. Ct. App. 2001) (Knopf, J.); accord Matter of Marriage of Patterson, 22 Kan.App.2d 522, 528, 920 P.2d 450, 455 (1996).