I knew a guy that was a driver for escorts back in college. In the late 90s it was over $1,000/night on average iirc. That included more than just sex though that was also attending a gala or sports game or other social events with you.

Per hour or per night?

That sounds like per hour. If you're curious about how the whole thing works parts of it are fairly above ground - community support subreddits and advertising websites with rates for example.

You can just browse the backpage for a bigger city to get an idea of prices. Apparently basic sex pays below $200h/h in Seattle (chosen at random), so those higher prices would likely be for a night/event/high class.