Remember too that "rare", "valuable" and "desirable" all have different meanings in the dictionary. I'm not saying it's not valuable or desirable. I'm simply saying that lots of times, people get the meanings of those three words confused.
In many instances, "rare" doesn't equate to value, and just because it's "one of a kind" doesn't necessarily mean it's "valuable". For example, my good friend Bazza's (Barry's) '71 VG Mexicana (my avatar pic) is one of less than 200 ever built, there are only 40 of them (or so) known to still be in existence worldwide, and his is the only one here in the States. Is it rare? Hell, yes! But is it valuable? In OZ or NZ it may be get a premium price, but here in the States- not so much.
With regards to your car (nice car, by the way!), the Market has spoken, more or less. You don't have to like it, but you're going to have to accept it if you want to sell it.