The belief in the economic theory of Spendenomics in which you can SAVE money by SPENDING money or by BUYING things on sale that you don't need. Closely related to Mommieconomics.
I was using the theory of spendonomics when I bought the lawnmower on sale. Now I am uncertain which closet in my apartment I should store it in.
The ailment that people, and especially women, suffer from around Christmas time that makes them want to wait in line for hours on end, buy unneeded items compulsively, and charge up their credit cards until they have to file for bankruptcy.