Here's an Idea...
1) Take a Radiometer and a Non contact digital RPM Meter...
2) shine a Laser beam on the Radiometer's Vanes
3) use the Non contact digital RPM Meter to take a reading of the RPM.
4) use that speed to calculate the Laser's power in mW.....
There you go... another DIY Laser Power Meter project...
BTW... eBay has Radiometers as well...
Jerry
I never said it would be as accurate as a LaserBee I or Kenometer....
But it should let you know which laser has a higher output..
Jerry