Oooh, I love a good debate about prices!
Personally speaking, I don't think my GS will lose the money that a comparable car (age/price wise) would over the years I own it. I agree with the comment made by 300 S - I think (and believe!) that the GS will be seen as the car Maserati got right...the 3200 marked the return, but had some weak points. The 4200 was a step up and was refined....and the GS was when it all came together. I thought that before I bought a GS and is the reason I bought one.
Will the appreciate? I dont expect mine to and would think that even the lowest of milage minters still have a little further to fall. However, just because the GT prices are falling, I dont believe we'll see the last of the GS's continue to drop. They may well do, but I dont thoink the person who would but a GT would necessarly want a GS, and vice versa.
I'm not saying the GS is Maserati's 355, but look at 360/355 prices - you can get 360's for £30k where as mint 355's are double that. The same could easily happen with the GT/GS.
In terms of the other cars, AC, MCV etc...IMO, if Maserati continues to grow in brand strenght, once a few more poeple get a taste for the marque, you may well see those rarer models becoming very saught after. Is that how you spell sort/saught?