Well, leica brand is like apple. It has consumers with strong brand loyalty. That explains the premium of apple and leica products.
Leica's products are also unique in a sense, it is, as far as I know, the only digital rangefinder(besides 1 model by Epson).
Rangefinder is a rather unique category as it is different and most street photographer like to use them. Discreet, quiet(no mirror flip) and the viewfinder. Yes, the viewfinder.
The viewfinder is more than 100% as you can see beyond what would be recorded by the photo. SO you will have lines in the viewfinder to box out which part is recorded. This, many photographers argue, is what photography is about- framing the shot.
You can frame better if you know not what is in the photo, but what you left out of the photo.
The problem with rangefinder is that its viewfinder is offset, so there would be problem with alignment. Here is where leica's expensive. They have a mechanical system(if i am not wrong, its mechanical) to correct for this offset. Pretty hard to do.
That's why most of Leica's M mount is prime lenses. I think there's only 1 model with triple focus length.
Note: it's
3 focus lengths, not a
range of focus length.
Again, leica's users must be some filthy rich, or professionals. Their cost of their body is spare change compared to the lens, which can be like 20k for a 50mm. The beauty of the price? it's f/0.95. Go figure.
But there's really something about leica that is unique. Check out these photos and determine for yourself whether is it worth it price.
http://www.digitaljournalist.org/issue0810/callie-bp.html
To me, leica promotes photography to a art form.