Why is Type Cover expensive?

The Logitech keyboard cover I used for an earlier iPad allowed use in more than one position because the tablet fit into a slot in the keyboard in either landscape or portrait. That said, the keyboard was nearly useless because it was so much smaller than a standard keyboard. The keyboard cover for the S3 is far better, throws in a useful trackpad (unlike the type cover for the S2) and is backlit.

I know quite a number of people who are productive with those Logitech compact keyboard covers. I'm not one of them.
 
I know quite a number of people who are productive with those Logitech compact keyboard covers. I'm not one of them.

I actually found them to be good/decent but was much better served by the flexibility of a separate thin Bluetooth keyboard (Keys to Go) enabling me to angle/space myself from the iPad in a more productive/ergonomic manner. I have yet to get my S3 Type Cover but hopefully the size and angle of kickstand will make it a bit more flexible.
 
I think they are expensive, because they are proprietary to the Surface. The nice little additions of back lighting, magnetic port connection, and now magnetized angle connection to the Surface itself are kind of nice.
 
Personally I think the type cover is a little overpriced, but not ridiculously so. Because it is currently the best option for the Surface line (in terms of perfect integration and lack of bulk), MS doesn't have to worry about a similar this quality keyboard at a cheaper price. That could possibly change in the future, but for now I can see why the keyboard is priced as it is.

That being said, I've seen the type covers go for less than or close to $100 regularly on eBay. It's just a matter of doing a bit of looking.