Erik 20% is pretty low even for adults. I know personally that i can save a buck a bag by cutting my purina with something else, but when i tried this it led to dismal results. Also keep in mind the coturnix are lovers of perpetual sameness and any changes in their sameness and they will make you pay=== "Change my feed, NO EGG FOR YOU! BAD KEEPER!"
Check around for local feed mills, I have 1 in a neighboring county that sells feed quite cheap== They make a 30% gamebird starter too, but I have to buy 1000lbs at a time since its a specialty mix... And since I am not set up to deal with the logistics of 1000lb of feed at a time I really cant take advantage of it now...
I know your in Florida, but not exact location, but if your able to drive to east Sumter county try Knights Farm Fresh Feed. They're located about 3/4 mile west of I-75 and SR 48.