We all know that restaurants need to make a profit on wine sales, but sometimes the prices are hard to swallow. Bring my own and suffer the corkage fee. But it depends on how long they have cellared it. It MAY be worth a larger mark-up for certain claret. Buy wine by the glass, and not go back to the restaurant.
Wine is an integral part of the meal.
Carefully shop for fairly priced wines. Depends on the meal. Low end of the list. I avoid the wine list, and bring my own bottle. I don't drink wine at restaurants.