I always presumed they always got enough dosh after the announcement was made; else they topped it up with the regular donations from the individual congregations to the circuit. I have never heard a special appeal or any resolution at the KH that asked for extra money for a Circuit Assembly. I would like to know what happens too.
Following on… Have you noticed that recently, at the Circuit Assembly baptism (depending on whether your hall has a pool near the stage), the chairman doesn’t say “Can you please reserve your applause until the final candidate has been immersed” like they used to? This means that you have to clap yourselves silly after every nut has taken the plunge. Your hands get sore and you feel like a performing seal. I notice that some candidates get louder and more boisterous applause than others, demonstrating that right from the start, as a JW you have to book your place in the popularity pecking order!