Apropos of nothing, the latest price list landed in my inbox this am, Chinese stuff in US$...
25 watt CO2 laser tube $127 or 40W for $158
pukka DC PSU for above $172
ZnSe or GaAs lenses various lengths etc $30 to $45
Cu mirror $16 quartz / silicon / molybdenum too
So you're looking at 400 bucks for something that will actually cut and etch etc, vastly versatile with PWM or potentiometer control on the laser, and if you bolt it to the Z axis that takes care of movement too.
Now I'm going to ask you, how much are you spending on "experiments"?
I know I wasted 12 months and maybe 20% of the cost of my CNC conversion by being cautious instead of being bold, determining what was needed, and going out and doing it.