(WSJ) - Good restaurants have a lot of costs to cover when they're pricing their wines, but some restaurateurs seem to take it too far. Lettie Teague on how to tell when you're overpaying.

ALTHOUGH I'LL ADMIT I'm particularly (perhaps even preternaturally) sensitive to restaurant wine prices, it seems as if they've gone up a lot lately—even more than they have in retail wine shops. Are restaurant wine directors actually paying more for their wines, or are they just taking higher markups? According to Chuck Ellis, president of the Newton, Mass.-based research group Restaurant Sciences, it's actually a bit of both.

Restaurant wine prices for the same wines are definitely higher overall, said Mr. Ellis in a recent phone call, and the reason is "a mix of higher wholesale prices and higher margins." Restaurant Sciences tracks thousands of wine, beer and liquor brands across tens of thousands of restaurants, nightclubs and bars in the U.S. and Canada, and in the past six months, the company's researchers found an "absolute increase" in wine markups.