u/IrmaBecx I'm more than 3/4ths of the way through a half reel of black/red I got in the summer. I do sell some of it to supply friends as well as to replace ribbon on a few machines I've repaired for others or gifted away (mostly to kids). It's gone a lot quicker than I would have anticipated.

And for the going cost of about five 2-inch spools at most sellers online, it's definitely a lot more cost effective. YMMV