Probably. But not always just that simple. Depends on the breeder and his objectives.
I hope to be breeding two pair of Koi this summer. My objectives will be to raise some good quality koi. My culling will be somewhat heavy. Meaning by the end of summer I plan on only keeping maybe 300 fish to keep through the winter. Of those 300 I will feel very lucky if I have 60 that I think are worthy of growing on for another year. The remaining I will try to sell at pond grade prices. My objectives are quality not numbers. If you find videos of the indoor ponds in Japan you will see thousands of young Koi for sale in each tank. Don't forget that they started with millions that are no longer here. It was mentioned in an earlier post that some domestic breeders sell to a mass market (petr stores). There is a market for those who won't pay more than $10.00 for a fish and in the pet stores they get what they pay for. Unforunatly most of these fish will not find a good home and will sadly just be replaced with another $10.00 fish later.