Splurge means to make a great display in any way. Usually, however, the display comes through expensive or extravagant things.
America’s most vibrant political force at the moment is the anti-tax tea-party movement. Even in leftish Massachusetts people are worried that Mr Obama’s spending splurge, notably his still-unpassed health-care bill, will send the deficit soaring. (The Economist)
Holding their purse strings in one hand and customized leashes in the other, dog owners found ways to splurge at this weekend’s Reliant Park World Series of Dog Shows. (The Chronicle)
Most precisely, splurge is a self-indulgence, with a common connotation of forsaking a more worthy pursuit, e.g. “With my last five dollars I splurged on a cheeseburger, although it left me without rice and beans.”