I agree with BC visitor
Make sure your friend is into wine first and has a palate sophisticated enough to appreciate a $200-$400 bottle of wine, or else you've just wasted a lot of money. One of my friends said they once tried a $100 bottle of wine in a restaurant and didn't like it very much, but they were used to drinking the cheaper stuff.
I know nothing about wines in that price range, but let's compare it to something most of us know something about -- cars. Say you're buying a friend who loves cars a $100 000+ car. Anything you get in that price range will be considered excellent by any standard of measure (horsepower, looks, cache, etc.). That being said, a friend who is really into wine will have some very particular ideas about what they like and don't like, so it becomes very subjective. Someone who is into cars might like a Mercedes S-class, but they'd LOVE a Porsche 911, etc.
I think you're better off dropping some hints as to what your friend would be looking for in a favourite wine and taking those characteristics to your local wine guy (sommelier??) and see what he/she can come up with.
