I partake in blind wine tasting nights quite often. Sometimes I organize, sometimes my brother does. There is a correlation with better wine being better more often. That being said you should know that an old Chateau with a good reputation will be able to charge more just because of their name and a newcomer won't. So expensive doesn't necessarily mean good but it allows you, if you know your way around a bit might help you out in determining which wine to drink and which not to in a restaurant.