What is the common expression for having a rich person's taste and poor person's budget?
This is often described as having "X" tastes on a "Y" budget, where people fill in their own humorous contrasts between something lavish and something frugal.
Two of the most common are "champagne tastes on a beer budget," and "caviar tastes on a tuna fish budget" (this last one was parodied on the show The Real Husbands of Hollywood, where star Kevin Hart was described as having "caviar tastes" but believing that caviar was spelled with a "K").
Live beyond one's means : to spend more money than one can afford to spend (MW)
What about "gold collar worker", in the same vein as white- and blue- collar?
Gold-collar worker (GCW) is a neologism which has been used to describe either young, low-wage workers who invest in conspicuous luxury...