my advice ...don't stay in a hotel. BA has some great deals but hotels have become very expensive, particularly the high end ones. Rent a short term apartment (there are quite a few companies doing this if you google it) and you can get an excellent loft style apartment for half the price. I would try and stay in Palermo Soho, Recolleta, or Palermo Hollywood. Soho is probably the best area as it is very trendy right now and has a lot of cool restaurants, stores, nightlife, etc. BA is a great city you'll have a blast.