Airlines love to excuse their change fees by simply saying that passengers should either buy unrestricted tickets or purchase insurance.

But for leisure travelers, unrestricted fares are often priced out of the ballpark and insurance doesn’t cover everything — like mistakes.

In this case, it was a relatively simple mistake. A client who had a tour booked in Europe thought the July 9 start date meant arrive in Rome on the 10th, when it really meant arrive on the 9th. But he didn’t notice it for over two weeks after he booked. Still, it was more than two months prior to departure and the correct date was wide-open. So, okay, he knew there would be a penalty.

Except, he was taking his wife and son along. United’s penalty is a minimum of $300 per person. Which made this a $900 mistake, even though the fare hadn’t changed.

Now, is there some effort involved in exchanging the tickets? Absolutely; more work, actually, than issuing them in the first place. However, our travel agency did all the work and none of the $300 fee goes to the agency. It all goes to United.

Another explanation provided for these sky-high change fees, besides the work, is the potential lost revenue for the airline. In this case, we are talking mid-week travel to Europe two-and-a-half months out. Plus, neither the original date nor the new date were close to full.

Which gets us to the real reason airlines charge these exorbitant fees — because they can.

I’m not saying airlines shouldn’t charge change fees, but it does seem that there should be a sliding scale. With hotels and cruise lines, the fees increase closer to departure. We have an airline industry that can change not only their fares, but the price of an extra legroom seat by the day. It doesn’t seem that they would have any problem programming different change fees into their system.

In addition, another option could be reducing change fees for passengers traveling together on the same record, which would be better for families. (Although making life easier for families has never been an airline priority.)

While airlines should reduce fees for changes made well in advance, they could raise the fees for changes at the last minute, when it might be harder to resell the seats.

A sliding scale on fees would also allow airlines to keep high fees during the busiest holiday seasons, which hotels and cruise lines also do.

Southwest already has the no-fee niche sewn up. Perhaps some airline looking for market share might experiment with a friendlier fee system? We can dream, anyway.