<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by SEA_Tigger:
Mainly that is to prevent me from booking a $250 Wed-Sun fare and then changing it on Wednesday to return Thursday for $100 when a Wed-Thr fare might be $1000, saving me - and costing the airline - $650.</font>
Wrong example. The change rules will not allow changes that do not satisy the original fare conditions such as a Sat Night stay.
The example you want to make your point is when there is another flight on Sun at a better time that is selling for $1000 and one wants to change to that one from the cheaper flight.