A professional flute sounds richer, clearer, and the metal it is made of -- rhodium, platinum, silver, wood, or gold -- is what gives it its characteristic tone quality, from earthy to ethereal. Custom-made professional wood flutes are very expensive (ebony) and require impeccable care. Most pros play silver or gold flutes.
If you are going to be doing a lot of playing outside, you'll need a cheaper flute -- nickel. You do not want to subject your more precious instruments to the vagaries of weather and changes in humidity. Not everyone agrees with me on this, but it's a standing rule for me. I have a beautiful nickel flute that has excellent tone that I use when playing outside. I suggest you keep your student model just for those occasions when you must play outdoors.
I see this post is a bit old, but I'll toss in my 2 cents.....many of the above posts are accurate, but the BIGGEST difference is that there are NO adjusting screws on a handmade/ professional flute. The flutes are built and regulated with small shims.
Why?
Adjustment screws can back out and your alignment can change.
Building and repairing flutes with out adjustment screws demands a much higher level of skill, patience and time...therefor more expensive.
Professional / Hand Made Flute
This is the voice of your artistic expression.
One might expect to spend $3000.00 to “the sky is the limit” for a professional or handmade flute. While there are some cost savings associated with buying a used flute, there is also a certain amount of risk involved. A used flute will most likely need to be adjusted and balanced for your personal touch.
Features of a Professional / Hand Made Flute
Body tube
The body tube may be made of varying grades of silver, gold, fused precious metals, and platinum. You also have the option of choosing the “wall” thickness of the body tube. The different materials and construction provide different tonal characteristics.
Soldered tonehole
Toneholes may be “"drawn" and "rolled" ” from the body tube, or they can be soldered on. There is much debate as to the difference in sound between the two.
Keys
French Key Pointed keys are standard on all non-touch keys. This method of manufacturing requires more skill and resources. The pointed or French arms focus the finger pressure directly on the center of the pad. Handmade flute do not usually have adjusting screws.
Scale and Pitch
Flutes are available today with several “Scale” and “Pitch” options. The scale is the relationship of toneholes to each other, the size of the various toneholes, and how they relate to the geometry of the headjoint. Some examples of scale are Bennett, and Cooper.
The pitch is the frequency at which the instrument is designed to play. The International standard is “A 442”.