How does this happen? Perhaps if a tag has no questions, it should take as much rep to use it as it does to create a new one?
So, it turns out that I was mislead for the 17th time by the interaction of the 'featured' tab with clicking on a tag. I find this completely counter-intuitive. When I am looking at a specific question, and click on one of its tags, I expect to see all the questions with that tag, not just 'featured' ones. Grumble.