I do not travel much. When I went to the airlines to buy a ticket the
Cost for the round trip ticket was $716.00. A friend told me to call her
Ticket agent and the cost was only $450.00 for the same ticket. Thanks
For having friends.

But how does that system work??

Lots of factors involved. Try booking the flight through Travelocity or Orbitz you may get different rates. I couldn't begin to list all the factors involved. I know, however, that you never ask the person in the seat next to you what they paid. It may make you sick :)