Yup if you want to guarantee your spot is there you pay for it ... otherwise you go on a waiting list and hope for best ... keeping the older sibling in one spots puts you and keeps you at the top of the internal wait list but is still no guarantee - sometimes a spot will come up two months earlier than they want and again they either take that one or I fill it and you hope another one opens again ... ultimately it is up to US if we want to forgo income for the right family - anyone who EXPECTED that from me would likely find my spaces filled