17 less mouths to feed. At 1/4 lb of feed each (roughly), that's 4 pounds of feed that will not be eaten each day. Even if we argue that it's less, say, 1/8 lbs a day each, that's still 2 pounds a day that would be saved
First thing is just move males. Any males that don't fit what you want exactly or are not absolutely attached to, go. If you can, sell them as pairs or trios with females that would go with them.
I used to offer deals if people bought multiples from me, usually 3+, but sometimes 2+ depending on...