Author modified his Zen CNC to use a laser. He built a nice case around it to keep the “laser” from shining out into someones eyes. I noticed Zen CNC’s have dropped in price, down to $360 (before shipping) for a 7x7x3. Not too bad of a price and they still look like a decent build. And its uses threaded rod vs belts the Shapeoko has (with a bigger table). Of course that doesn’t include shipping. The laser on the other hand is about $260….
http://www.instructables.com/id/Using-Zen-Toolworks-CNC-with-Laser-Engraver
http://zentoolworks.com/product_info.php?cPath=14&products_id=74
http://jtechphotonics.com/?product=1-7w-445nm-laser-diode-and-2-0-amp-adjustable-driver-kit