I've had glass pipes that break, it's not a fun experience, and I noticed one of my old spoons has this stress fracture type crack in it. It doesn't wrap around, it's like 2 1/2 inches long, and it's inside the glass, so it's still keeping smoke in. Heres a few pictures, hope you can see what I mean. http://postimg.org/gallery/4blf8vie/d1d99090/ Should I sell it or is it nothing to worry about?
It is useable with those flaws. Buy a new one when you can afford it. Throw this one out to avoid potential problems that will come.
Its usable i had a pipe that had a crack on the inside and it was good eventually fell apart in my pocket some how use it until it breaks.