Originally Posted by
aceman
Agree, which I've heard of -though only with AA now i think of it. However the agent called it a 'differential fare' twice while I was chatting to her. Makes booking these quite annoying for someone that regularly changes dates.
Realistically though you either pay a discounted dif fare or a standard t class fare then if you change you still pay difference in price and change fee. The only difference is either paying more initially or paying more for the change.