Interesting research to back it up:
The luxury goods market, once only accessible by the ultra-wealthy, has been transformed in the past few decades to be a world within the reach of middle class consumers. However in the wake of the growing international financial crisis, governments, societies, and individuals have been forced to make substantial changes. As such, consumers have begun shunning outward displays of wealth. Heavily branded, self-promoting luxury products are being forced to reinvent themselves due in part to the deep pains of the financial crisis, especially hitting the lucrative middle-class market. This phenomenon has manifested in a trend, dubbed "Luxury Shame." By using psychoanalytic theory, this paper seeks to examine the development of societal prohibition in the form of luxury shame and the internalization of this prohibition in individuals as guilt and shame.
One caveat: It does not only affect the middle-class, but also the very rich.
H/T: CSN Abstracts