Wow, what a great question....
I think that it really depends on the individual doing the "desiring." There are vintage carres in many designs that are sought after by collectors for many reasons...design, artist, rarity, colorway, etc. The grail scarf can be 70 years old, or a favorite but out of stock colorway from the current season.
some scarfies like their scarfs crisp and new, others love an old, well loved carré. Some collect by artist, some by motif (equestrian, florals, etc).
If you are looking to add to your collection, I recommend you search the threads here, and try to hone in on what style of design YOU like, as well as what colors and size is good for YOU. IMHO, there is nothing sadder than a beautiful Hermes scarf that never gets worn, no matter how rare of special it may be...
http://forum.purseblog.com/hermes/which-scarf-pointu-pochette-are-you-wearing-today-113322.html
http://forum.purseblog.com/hermes/your-grail-scarf-121359.html
Also, you might find the mousselines more wearable, or the cashmere, or maybe the 70 cm.....Its a whole world of choices.
There are a couple that are always HUGE on ebey, recently we saw Kermit Olivers Madison Avenue hit over 1200K, and Rencontre Ocean and Grands Fonds in certain colorways are always very popular. But if these are not scarves that you love, or would wear, then they are really not "desireable" for YOU, if you know what I mean.....
you can see hundreds of 90 cm scarves here...
www.preciouscolors.com
good luck!!!
