The site fee is like $325 and I believe you only get an hour.. We called about our date-- and practically the whole day was booked already.. 6 months out.
We were going to use it as a back-up plan in case we can't get into the Carltun until 5 30- but 300 bucks wasn't worth it to us-- the pics I have seen from there are great--- check the review board and do a search for Old Westbury.