A typical helicopter gets around 10 miles per gallon of fuel and they can usually go up to 250 miles on a tank of fuel so a helicopters fuel tank is around 25 gallons and fuel for helicopters cost from $4.50 to $7.00 per gallon so at $4.50 per gallon it would cost $112.50 to fuel a 25 gallon tank and at $7.00 per gallon it would cost $175.00 to fuel the 25 gallon tank.
Now that's just an estimate as I'm not entirely sure on the size of the fuel tank on a helicopter as it could be larger or smaller.
I've also read on a blog before that it took someone $1,000.00 to go on a 1,500 mile trip in a helicopter.