1) Get out of this mentality that "I have $200! I must buy the coolest toy that I can with $200!" Buy the best toy you can. Price does not determine worth.
2) 5.1 headphones are indeed a gimmick. You only have 2 ears. ANything that you can do with a 5.1 headphone setup, you can do with simple stereo headphones and emulation software.
3) For $200, get yourself a nice pair of headphones before you worry about getting gimmicky 5.1 headphones (Because they just don't work... the 5.1 is a gimmick, and you'll end up with headphones that aren't good as 5.1's and aren't good as stereo headphones.
4) If you want to get into headphones, start asking the people who know over at head-fi.org. Grado SR-60 headphones are a good starting point, as are Etymotic ER-6i canalphones.