Another part of the problem is the travel agent/travel manager/purchasing department who figure that all that matters is ticket cost, and don't take into account the cost of the time. Because so many people who travel are expected to do overtime for nothing - 'it goes with being a professional person' - they think it doesn't matter. I've always put the full hours on the timesheet, so that there is a charge......
Now I'm self employed, it's really up to me - but at my standard rate of £100 to £150 an hour, you have to save an awful lot to make cheap flights worthwhile when you consider how much longer it takes me to get to and from Stansted rather than Heathrow.