And just to refresh my memory -- you can buy a ticket that is only for the party? As in, you don't buy a park ticket AND an OBB ticket?
(I know OBB tix get you into the park a couple hours before the bash starts; I'm just considering doing this for the first time, as a special 16th bday treat for DD -- tacking OBB on for the night of our arrival, which is a day we don't have regular park tickets for.)