My bottle is actually glass, it has a date on the bottom of 1945 (possibly 46), though I think it was made a bit later. They went from glass, litho-tin, and back to glass. It's also unused, maybe only used once or twice, but I doubt it. The cap feels like ceramic, not like plastic. It makes a nice little "ping-ping" sound if you tap it with a small little screwdriver head.
The Odorific II is in a very tiny little glass bottle, but it is very potent and lasts a long time. You can take a cotton ball (or I take one of my mom's makeup pads, works a bit better), put a few drops on, and put it between the disposable bag and the outer bag, I find that if you place it in one of the top corners, you can smell the scent much better since more air escapes from there.
I think my two bottles were less then $5.
~Alex