Re: but that's the same as everyone elses review!
"there you go... could make it yourself for 70 quid for a single unit. reduce cost by at least half for bulk purchases and injection moulds."
One thing you forgot in your DIY costs are the LCD display and the mechanics for the buttons. Which brings you certainly above the $105, as labor cost has to be added at the very least as well.
And even with bulk purchases, I doubt there is much of a margin in this, and I suspect that this is rather one of a few dozen "samples" that have been hastly produced in a kind of DIY fashion to finally show "something"...