One way to upgrade your flute and keep to a budget is to substitute the head joint for one of the many head joints produced by Powell Flutes. The variety available is truly amazing, from different materials: sterling silver, Aurumite® 9k and Aurumite® 14k, yellow, rose and white gold of different weights, platinum and grenadilla wood! Furthermore, there are now four different "cuts", all of which produce the famous Powell projection and colors, but have slight differences that appeal to each player in a very personal way.
The best way to try out head joints is to make an appointment, and then experiment on every head joint you can possibly try—even ones that are out of your price range—in order to get an idea of what you like. Because there really are no "shoulds" in choosing a head joint: there is no point in choosing a head based on what your teacher or a famous flutist plays or what you think you should like. The only important things is how you feel playing it, and how it sounds TO YOU as you play it. Ideally, you can also get important feedback about projection from me or another musician, standing at some distance from you as you play.
You should play passages in all registers and dynamics, legato and articulated, in order to get a feel for the response in these different musical situations. Take your time and have fun in the process—with luck and a relaxed, experimental frame of mind, you're likely to find just the right head joint FOR YOU!