Why do you think it's cheaper to produce the blank with the cut-out? These blades aren't cast in a mold. They are either CNC-cut or stamped out of a large sheet. The drops from the cut-outs are waste. Dies or programs are more complicated, waste has to be disposed of. Unless you've figured out what they're doing with all those funny-sized steel donut holes, beyond recycling them for scrap value. I'd be terribly interested to hear if they are NOT simply scrapped. Ka-bar doesn't smelt its own steel. I don't know for certain that the cut-outs are more expensive, but I haven't heard or imagined a compelling argument why they would be cheaper yet.
I'm convinced the cut-outs are for carry-weight and/or balance. Lots of people do count ounces for their outdoor gear, and weight in the handle increases user fatigue and does not contribute to chopping power.
Might save YOU money on shipping 'cause the knives are lighter!