Not so amazing, really, if you think about it. I'm kind of a sucker for goofy projects, but it took me over an hour to make a rather simple version of your choral. Even if I were certain of winning, $100 per hour of concentrated work is not that great. And competitions of any sort are notoriously unpredictable, so I must multiply that $100 times the probability of winning, say an optimistic five percent: thus, effectively $5 per hour. Really less, because if I win I have to correspond with you, listen to your student orchestra, etc.
This is not to criticize you, just to point out why most folks might not take the time to respond to your offer.
This is not to criticize you, just to point out why most folks might not take the time to respond to your offer.