Yes, 2007 anthracite is extremely desirable. However, it depends upon the leather quality too. Is it smooth or heavily distressed and wrinkly? It's chevre goatskin too, rather than the current lambskin. Most followers prefer the chevre leather.
All the 2007 chevre bags I have seen in person have had beautiful leather. I had an anthra Twiggy that I sold and missed it so much, I purchased an anthra City just recently (it is actually waiting for me when I get home - haven't seen it yet in person). This is a gorgeous color as it is grey with hues of either blue or green. If you are being offered one in good condition, I would grab it!
I just got an 07 anthra and it is so beautiful - the distressed (wrinkly) leather is so soft and luscious.
the color is different from the more recent anthras i have seen, some of which looked kind of washed-out. very deep undertones of blue/green. i`d say go for it !
07 Anthra is gorgeous, and Bal leather is naturally smooshy and distressed. I think you should go for the bag, especially if you're managing to get it for a deal since 07 Anthra is hard to find nowadays