what kind of helicopter (a) is fuel-efficient and (b) costs less to maintain?

We have drones in Idaho. You from Alabama or Mississippi?

It's called a drone.

No helicopter is "fuel efficient". The nature of helicopter flight uses a lot of fuel.

Helicopters don't stay "up in the air for hours". The small helicopters that are typically used for TV news reporting have a limited fuel capacity. They normally don't fly for more than 45-60 minutes at a time before they have to land and refuel.

With any helicopter "fuel-efficient" and "costs less" are relative terms. Copters are expensive to operate, since on most types major pieces are life limited - that means after X number of hours you are required to replace them, no matter their current condition.

The types Vincent mentioned are 2 seat piston powered copters - they really do not have the payload to carry a camera mount and a camera operator. And since they are piston engines, figure on a $20,000 engine overhaul every 1500 flight hours or so.

There is a reason almost every new copter you see is a Jet Ranger - they are 5 seat turbine powered aircraft. They can carry a professional camera mount, and the turbine engine is more reliable. The Robinson R55 would also be in the same category. .

Cheapest helicopter to own and operate is probably the Robinson R22 or similarly sized Yo-Yo 222, Schweizer 300 or Brantly B-2. The cost per flight hour will be around $150.

You flyboys crack me up!

You are about to spend upwards of half a million dollars and your are looking for answers from people typing in their one-bedroom apartments. Get serious.

Use a drone. If a helicopter is in the air you need to worry about it possibly crashing and people being killed.

As for the cost, there is a saying "if you have to ask, you can't afford it". This seems like a good place to apply that.