Here in Queensland my lads went to a low cost catholic co-ed school, and while some went overboard for the 'formal' as they call it here, most lads just hired suits, and the girls' Mums or Grans made their dresses. As I mentioned before, one lad chose to go, the other chose not to, but he did go in the end.
He became a high school teacher, teaching 15 year olds to school leavers, and one year the girls in his grade 12 ancient history class persuaded him to go to their formal. He did go, and there is a wonderful photo of him sitting, big grin on his face, surrounded by 8 beautiful girls in different coloured evening dresses.
The children love it really - it is their first grown up function, they are taught the etiquette and behavioural rules beforehand, and they have a great time. My part of SEQueensland is not a snob area - perhaps that helped. Maybe it is a snobfest down the Gold Coast or in the posh inner suburbs of Brisbane, but while I would have preferred something a bit simpler, it seemed to work well here.