From lightobject.com .....the 2012 Commercial DSP CO2 Laser Engraving/ Cutter Controller = $450.00.
This includes LaserCAD as the software. This type of controller has a microprocessor built-in for high frequency pulse width modulation (PWM) of the laser for graduated power control. It is not as necessary for vector cutting, but is certainly needed for raster-controlled engraving.
Also includes a LCD control panel.
Alternatively one could use CamBam + and Mach 3 bundled cost = $315.00 (http://sites.fastspring.com/hexray/product/cambam_mach3
), i.e. the CamBam store.
Mach3 is standard CNC software, but not truly software for laser control. Best used for 2D or 3D milling. CamBam is a necessary software to turn design code, such as a DXF file into G-codes. Mach3 is essentially a G-code reader to run stepper motor controllers or TTL devices. I.E. it will turn laser on/off.