Remember these three things about luggage
1. If you are going on a trip that is 48 hours or less, you should be able to fit everything you need in a smartly designed backpack or small duffel that could, if need be, fit under your seat (plus a hanging bag that most airlines will take and stow for you if you ask).
2. If you have to check bags, most good rewards programs allow you at least one free. So make sure you're taking advantage of that.
3. If you're in a paying situation, you can often just take your bag through security and then check it at the gate for free (flight attendants admit they'll do it). If your bag is too big to fit through security, and you're going away for less than a week, ask yourself: Who do you think you are, anyway?