Grey Flannel is one of those love it or hate it frag. It is a very strong, masculine, green, mossy, lots of violets fragrance. It has that "old man" vibe. I don't think that this is a safe blind buy even if you get it cheap.
Try Azzaro Pour Homme. It has that "mature" smell as well but definitely smells better than Grey Flannel.
I own both and I prefer Azzaro PH.