How much is a personal trainer?

I believe it would be in line with as others have said, anywhere from $25 for entry level and smaller markets to $200-300 per hour for big time pros who are booked with high profile clients and speaking engagements.
It certainly depends on your location, market, facility, expertise, etc.

As a trainer, it’s the same as any other service industry, and you must charge what you believe you are worth. You must cover all types of costs, be compensated for your time, and make a profit. If you are getting into the game, I would perform market research in your area.