In the most of countries the travel costs are borne by the au pair. Please read the newest regulations valid for your host/desired country of your interest!
Arrival of an au pair: Even in the case you, as a host family, want or have to, partially or totally, take over the travel costs, we recommend you to send beforehand the au pair to be an air ticket instead of the money. The other possibility is to reimburse the costs after her/his arrival.
Return ticket of the au pair: When you are happy with your au pair we recommend you to cover partially or completely the costs of her/his return ticket.