The best idea I have is to rig a mandrel and platen for a GRS disk to mount in a drill press, and then a fixture to hold the graver.
Lindsey's sharpening guides for use with stones are probably a better option, but like all his tools, you'll need to let go of some money.
A DC motor from a treadmill could be used to make a nice stand alone tool. In all cases, the GRS sharpener is over priced unless you can write off the cost.
Then, there is the cost of a microscope, air pump, engraver tool, and engraving balls for the amateur that wants to work like he's taught at places like the GRS school.
Sharpening gravers with a drill press
I hadn't seen this one before. The electronic angle gage is clever and they are cheap enough now.
DIY powerhone for graver sharpening
This one will work with less vibration without that giant set screw in the arbor.
DIY: Power hone
This is a good idea. These watchmaker's lathes come up for sale on Craigslist often here, they're probably easy to find in Denver, too.