Not sure why, I guess it's because they weren't produced in such large numbers, but they sell for much higher prices than e.g. N900 or N9.
Well, I guess it was the latest and greatest.

Some people seem to think they're priceless collector items which - well, I guess it's everyone's own choice, but I think it's mostly BS.

Sellers make a big wave, try to sell it for thousands (?) of €€€, but I've never heard of any buyer actually buying one for anything even close to 1000€.
And by big wave I mean they advertise the same item multiple times and generate false sales that are way beyond reasonable to make potential buyers believe that the phone really is worth that much.
And also making big talk on various online forums.