My wife has an acquaintance whose husband runs some sort of bistro. He charges 6 dollars a glass for his "house" wines. House wines being Charles Shaw. I realize that there are expenses involved in serving wine, such as the server's time, dishwashing, breakage, rent and utilities for the establishment, etc. But how much of this should be passed on to the consumer of say 50 cents worth of wine (estimating 4 glasses per bottle)?