Sorry, but I think that either he is pulling your leg, or there has been some sort of misunderstanding. Renting aircraft in the USA (or Canada) is certainly much cheaper than in Europe, but you can't get a Cessna for US$15 per hour. Not one that you'd be willing to trust your life in, anyway!
If you do an Internet search for "Florida flight schools" or something like that, you'll find many websites that will give you the actual prices currently available.
