Doreen Winkler, founder of wine subscription service Orange Glou, told Chowhound that the idea of restaurants maliciously marking up their wine prices tends to be exaggerated.

"Pricing is determined by a mix of costs and profits, and it varies based on factors," she said. However, that doesn't mean restaurants don't mark up their wine.

A restaurant's wine pricing depends on its business model (casual versus formal), its location, and expenses like staff wages and rent.

Often, state and federal taxes apply for the wine to be shipped from the vineyard to the wholesaler and then to the restaurant, and additional sales tax when you buy a glass.

Many restaurants use the industry standard markup between 200-300%, while others use a sliding scale, meaning cheaper wines have higher markups than expensive wines.

Winkler says restaurants won't go overboard with prices. "It's important to understand that the business must cover its costs to continue serving customers," she said.