Hi Carsten, For an expensive way to give it a try without air check the thread:
http://www.engravingforum.com/showthread.php?t=4
Here are prices of the AirGravers
Artisan AirGraver handpiece with foot control idle adjust with dual
regulators: $844
http://www.airgraver.com/Artisan-AirGraver.htm
Classic AirGraver handpiece with foot control, idle adjust with dual
regulators $1244
http://www.handgravers.com/Classic.htm
or Classic AirGraver Handpiece with PalmControl $2690
http://www.handgravers.com/PalmControl.htm
The difference between the Classic and Artisan is the stroke collar. The
stroke collar on the Classic provides the power of several sized handpieces
in one. It is similar to setting the back swing of a hammer hitting a punch.
It can be set at a short back swing or longer one. The PSI flow through the
foot pedal or PalmControl controls the power and speed within a given stroke
length setting. Think of it similar to gears in a car. Set it in first gear
(short stroke) and you have good low end delicate control... or set it in
fifth gear and you can cut much deeper than in first gear. We can still cut
delicate lines in fifth gear but it is easier to cut delicate lines in first
gear. If thinking about this analogy with a car, then the Artisan is fixed
in 3rd gear.