This will be some deal and where the price point should be for a multi layer tour ball.
If Costco can make minimum of 15% profit to market 2 dozens brand new 4 layer urethane covered golf balls under $30..... things to come with the golf ball industry.
First instinct I want to say Callaway, since they had been marketing the Callaway for years. It would be a natural transition for transform the OEM brand into the Kirkland brand for lower price point. They had been doing this for decades.
Then, I thought about the Nike's exit of the golf equipment segment. The manufacturer of the Nike golf ball will be eagerly looking for replacement to keep the volume roll off the end of the assembly lines. No volume, or not enough volume to at least break even, means the end of the business. So I'm voting for the Nike's original manufacturer making the Kirkland brand.... Look for the 2016 Nike golf balls for comparison, not sure which model come closer, the black RZN is a 3 piece and the NIKE RZN Platinum Golf Balls is the 4 piece urethane covered golf ball. I did not check the dimple pattern but I would not be surprised if the dimple patter is slightly modified to avoid pattern right dispute.
My vote is 'NIKE"