Yeah, the startup costs of helicopters are large. A Marine quartermaster once told me that it costs $N,000 just to turn a military helicopter on, because after you turn it off you have to do a bunch of maintenance tasks no matter what. And chopper technicians aren't cheap.
Flying a drone is much easier and cheaper than flying a helicopter.
Sure, you can go ride a chopper to look for the person, it's about $500 an hour
Not to mention risk and hard to reach places.