Am I missing the part where it says this is based on a couple leaving together?

Furthermore should you really count the flight bonus and last months wages as being part of some bumper pay out at the end of the year? Probably not. The flight money is a reimbursement of an expense and the wage is something you've worked for. These are things you as a teacher are owed. The fact that schools would seek to gloss them up as some kind of golden handshake just shows what a sorry state of affairs esl is in in this country.

If you pay a contract bonus then fair enough but it is not close to 4500usd