I have never met one earning that, you might find one or two working in big budget film / television commerical production.
There are lots of tall tales about earning £350 per hour flying a £1400 Phantom drone but when you ask who? It goes very quiet.
Drone flying is fun..that is compared to other jobs like cleaning toilets so pretty much most estate agents, surveyors etc buy their own rather than pay an external.
I have seen some smaller local TV newsrooms using a Phantom (small drone) for news shots, the drone belonging privately to one of their camera operators and not the actual broadcaster. I'm not sure how the insurance would work on that if there were an incident.
Some prices for drone stock footage are ridiculous, more expensive than hiring a helicopter, I have seen £400 for a 10 sec shot advertised of a few boats in resting in a harbour, lovely shot but nothing special.