Originally Posted by
kjnangre
The difference between what you actually paid and today's current price for the flight you want. Historical prices are, well, history.
You could wait for a schedule change and then make the change for free.
There was a schedule change, I made the flt. change I wanted for free.
But knowing what the rules are will be useful in the future..
But for DL Vacations, DL does not see what I actually paid [I bought a package], so knowing what I would have paid on the date of purchase would come into play for computing "fare difference".