Ask HN: What price should I charge for corporate DevOps and Big Data training?

I used to do backend/frontend web dev training a little over $1,000 a day. I've since then I've been doing a lot more work with Docker and Apache Spark. I'm beginning work with a new training firm, and they want to know what my daily rate is. I know I can charge more for my new topics, but I'm not sure what number I should give. Some insight would be much appreciated!