More in line with Mutt's response, I look at departure and destination fuel, and tanker acordingly to get the trip cost(down and back) to the minimal cost). Always hated to leave a jet parked overnight fuel of fuel, tires tend to set,(thump thump thump on taxi the next day)wet wings have a higher preponderance to leak...not to mention overall higher landing weights, longer rollouts, and more brake and tire wear...