Whether you call it “corkage,” “BYOB” or “brown-bagging,” most wine drinkers want the freedom to occasionally bring a special bottle of wine from their personal collection into a restaurant. Where state and local laws allow the practice (it's complicated …), it's often up to individual restaurants to choose whether they want to permit corkage, and if they do, what fee to charge per bottle.
Restaurants—which would prefer you to order off their list—argue that they should be compensated for the use of the glassware and the service, as should the servers in their tip. Most wine drinkers would agree to some extent—fees of $15 to $25 are now considered typical at restaurants licensed to sell alcohol—but some of the corkage fees charged are so high that they are meant to discourage BYOB. Common BYOB etiquette dictates that you should always ask the restaurant first, make sure the wine isn't already on their list and order a bottle off their list as well. But after those niceties are taken care of, what fee range is reasonable so that neither the customer nor the restaurant is taken advantage of?