Well, I've played with it, how they do it without removing the board is beyond me as well, but one thing I can say, I sure wouldn't do it for any less than $600, it's far to much work.
Snork, you have to remember, what takes you 20 hours and you don't care because it's not what you're doing for a living isn't fair to say that somebody else is ripping people off. If I didn't want to do custom work for a career, but could still do it for myself, I would say that $400 for a vine inlay is a rip off too, but that's only if I was doing it for myself and wasn't counting my time. Doing it for a living I have to charge for my time, same way a mechanic charges to work on your car at $60 an hour.
$30 won't buy you the LED's if you're getting good ones, and I sure as hell wouldn't build a wiring harness, inlay LED's, remove and reglue a fretboard and then check all the frets for level etc etc etc for what Sim's is charging. The LED's and a proper wiring harness will cost you around $75 in materials alone with circuitry etc. Something most people forget is that in order to have the LED's last as long as possible, and have all colors burn at the same candle power, you are in need of resistors etc, plus a proper circuit to power them all, you can't just plug LED's into a 9 volt and expect them to last. Then you have to actually wire it all up, test it, etc etc etc. $600 for what they are doing isn't out of line IMO.
As for half a brain and some luthierie skills, I charge $30 just to change a set of strings (why? because I feel if you're not smart enough to change your own strings you shouldn't be playing in the first place) which just proves that not many people out there want to remove the fretboard on their favorite guitar.