If a man told his wife, "This is your Get on condition that you give me 200 zuz (~$10,000)," then she is divorced, and the Get takes effect retroactively to the time of giving the Get, at the moment when she gives the money. Therefore, if the Get is meanwhile lost or destroyed, it still works.

If he said, "On condition that you give me the money within 30 days," - then if she gave him the money within 30 days, she is divorced, but if not, she is not divorced.