If you are planning on independently traveling to meet a lady, it is very important to make your payment at least a week before you are to travel. So there is plenty of time to contact the agency and the agency has time to contact the ladies, and organize the meetings with the ladies and work with their schedules.
Here is an example of how NOT to do it. A guy flies into the lady's country Friday night and is due to leave Tuesday. The guy makes the purchase, when he gets to his hotel room after midnight. Unfortunately the agency is not working that weekend because they received no notification that the man was coming. By the time Monday rolls around, the agency sees the request, contacts the lady, but she is busy at work, and can't get away to meet him. So, no meeting takes place. Therefore making the purchase a week in advance is very important.