WordNet (r) 3.0 (2006):

conspicuous consumption
    n 1: buying expensive services and products in order to flaunt
         your wealth

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "conspicuous consumption":
   carpe diem, dissipation, extravagance, incontinence, intemperance,
   lavishness, leaking purse, loose purse strings, overgenerosity,
   overgenerousness, overliberality, pound-foolishness, prodigality,
   profligacy, profuseness, profusion, reckless expenditure,
   reckless spending, squandering, squandermania, waste,
   wastefulness