<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by misstree:
However, you are missing the point of the $75 change/cancel fee that the airlines (and travel agents) impose. Obviously it is used to discourage people from buying a ticket for travel two weeks from now and then decide to "change" it for a trip tomorrow. </font>
The requirement that the passenger pay the difference in fares for the fare bases which are available eliminates this problem. (I.e., airlines don't have to depend on a $75 change fee to prevent people from changing the ticket for travel two weeks from now to travel tomorrow, when the fare basis for the former is $250 and the fare basis for the latter is $2000, and the passenger must pay $1750 before any service fee is added.)