Hi,
your first flying job can pay as little as approx 1500 UK pounds per month net on a 2 crew aircraft. Moving overseas with the required experience you can make approx 11000 UK pounds net per month.
If i was 21 years old siting in a nice turbo prop aircraft getting 25000 grand per year i would be content in the short term. My goal however would be to move on to a job where the money was better.
Your ideas change as you get older. Starting out in your career you will be happy to take any job to get on that first rung of the ladder. With that may come a lower salary than you hoped.