Podcast Fees?

I have a real question. I am getting on podcasts to talk about a new book. I am used to getting scams all the time asking for $ to be on their “podcast,” which I ignore. But, I recently requested to be interviewed on a real podcast and they want money.

Is that a thing? I’ve been on or scheduled to be on 13 podcasts, some of them with very large audiences, and never been charged to be interviewed. I suppose it is part of a marketing budget, but it’s hard to say if it’s worth it.

Thoughts?