I found one last summer at an authorized dealer online that was getting rid of their Montblanc watches and they happened to have 1 single watch left, and it happened to be a Greytech. I was so close on pulling the trigger, the price was really, really good. I still somewhat regret not doing so.
I feel these are definitely underappreciated. Iunderstand that the first TimeWalkers with an ETA movement did not get much love but find the case design to be truly special and yours definitely has a very nice movement, too!