Ahhh. But AA-SABRE has implemented a system called T-REX. It requires a fee when reissuing a ticket that requires one. Or else it won't print out the ticket.

The agent MAY override it. But his/her name is on the line as to why the fee isn't collected when persued by the ticketing department.

Basically that's what you're doing. You are CHANGING the routing of the original ticket, hence the change fee.