The example from Nico is ok, but I think it is even more difficult if we start to discuss the value of different AP Royal Oaks:
Most of my (non WIS!) friends think the/my RO is an somehow "ugly" watch. They don´t understand why I spent money on that, having some more nicer watches in my box. ...
Well it is their taste, not mine and I have to spend MY money for it - anyway 
For us WIS:
Ref. 15202 vs 15300 - the key differents are the movement and the case, aren´t they
Sometimes I get the impression that some WIS think the 15300 is "second class". Most of them quote the "sophisticated" movement and the "slimmness" of the case - 15202.
Of course there are some good points for the 15300 and it was my choice for a reason ;-)
OK, but what is about 15202 vs 5402 (or 25402)? What makes the differences in value, from your point of view? Movement, case, clasp, "logo" above 6, vintage charm, rarity, ...
From my point of view it is quite interesting to discuss value with regards to the AP RO (mentioned above), but I think we could discuss the PP 3700, ... 5711 as well, couldn´t we?
Anyway, to me both "styles" RO & Nautilus are classy and I appreciate their subtle value, compared to the most watches from Rolex (just an example!)
@ppplater: I really like that kind of questiones/thoughts. Thanks!
Oliver
ps: I have choosen the examples above, because most of us will know it quite well