Honestly, I charge a lot more than $50 an hour, but I can create many maps in an hour's time, depending on what kind of details are involved. I couldn't create a city map, or an entire detailed dungeon level, but single, simple structures, small villages and general wilderness or cavern maps - it can be done (at least by me), however, I generally only take commissions from publishers these days. Consider that my last 2 commissioned maps were for Raging Swan Press and Paizo Publishing.