WHY DOES WINE INSPIRE so much fiscal madness? From collectors who cram cellars with thousands of bottles to Pinot Noir lovers willing to cash out bank accounts to build wineries, a passion for wine is a remarkable—and often risky—driving force.

This is especially true for oenophiles who decide to open wine stores. The margins are thin, the hours are long and the competition is fierce. They may realize their dream only to discover the reality doesn't include much of a salary or many weekends off.

For Matt Franco of MCF Rare Wine in Manhattan's West Village, starting his own store should have been easy—after all, Mr. Franco has been in the retail wine business almost all of his working life, as a salesman and a buyer. And yet, three and a half years after investing $12,000 of his own and $50,000 of his family's money, the 34-year-old hardly brings home a paycheck even though his store is making a profit; instead he reinvests in his business.

He still faces a number of challenges—like wholesale sales reps who won't sell him certain wines unless he "supports" their other products (a common sales ploy) and competition from all over the world with the advent of online wine sales.