A new study from the Wine Market Council finds consumers are no longer willing to pay ever-higher prices for a glass of wine. In San Francisco, a glass of wine in a restaurant typically will cost $24 a glass.

This is premiumization in action, sell ever fewer quantities of a product at ever-higher prices, and then wonder why sales start slipping. In just two years, the average glass of red wine at Prospect, a San Francisco restaurant, has jumnp to $21 from $18 – a 16.67% increase

WMC research found only 7% of wine drinkers are willing to spend more than $20 for a glass of wine, and only 15% are willing to spend more than $18.