why are miniature scanners for printed text so much more expensive than webcams?

Factual Questions
1

my googling so far suggests that the cheapest pen shaped scanner for capturing a few lines of printed text for digital notes sells here http://www.amazon.com/WizCom-QuickLink-Pen-Handheld-Scanner/dp/B00004VUHO for around $100. There are a few other gadgets on sale elsewhere for a lot more than that.

Meanwhile usb webcams sell for around $10. $100 is the target cost (not necessarily now realized) for a low-end Android smartphone complete with a camera.

So what’s the deal here? Just how freaking is expensive is it to make a video camera optimized for capturing printed text? Ok, so a high end model is going to have a built-in computer, lots of memory, battery and various other features for the most (in)discriminating consumer. But where is the low end model that I can plug into the usb port of my laptop and get the job done cheaply and efficiently?

2

The device you linked to runs on batteries, does the optical character recognition on device and stores the text.

I’m guessing you won’t be able to find a tethered USB one that does everything on PC that is also pen-shaped – the market for something like that would be entirely too small.