Oops. I didn't realize there were different options beyond GSM/not-GSM, so I was comparing the $829 64GB/GSM to the base unit.

$150 was a number just pulled out of my ass.

I'd be very curious, though, to see the statistics for people reading eBooks via the free Kindle applications versus the Kindle hardware devices. I strongly suspect that you'll find that even with the additional fiscal overhead of the device, there are far more people reading eBooks on the hardware than the software. Because actively lit devices suck ass for reading.

Optometrists constantly deal with people who have eye problems due to computers, to the point where they came up with a term for it. But I, at least, have never heard of Book Vision Syndrome.