I find it humorous when folks say the cost of a product costs too much and list some ridiculous lower price. If you feel it costs too much, then you're welcome to devote time and resources to make something similar. Then feel free to price it low. But don't forget what it takes to get a new product off the ground; overall costs to design, code, produce working prototypes, test, tweak and retest, finalize a finished form, manufacture, promote, ship and sell. A lot does go into getting a new product off the ground, especially for a company that doesn't already have past experience or their own facilities to use.
The way I look at it - it costs $600. That's out of my price range and in all honesty, if I owned one, I probably would have found less than a half dozen times I would have needed to use it for a few possible power issues I've come across building computers and helping folks troubleshoot broken computers over the past 10 or so years. So, would the $600 price justify my purchasing of one? Absolutely not. I'm just an above average computer knowledgeable person that enjoys working with them when I can.
I know a couple people that do a lot of work on computers for their normal work life - they may find it justifiable to spend $600 on a device like this.
I won't be picking up any tool like this unless I come across a lot of money I have nothing better to do with, but I did enjoy reading through the review. As
@R-T-B said, I wouldn't mind playing with one because it does pique my interest, but I wouldn't buy one.