I am not an engineer, but I would think the first 30,000 feet are probably the most expensive.
That could well be the answer I was looking for. I don’t know either. But all the logistics of getting a successful launch in the air versus on the ground, just seems mind boggling that it could be any easier or less expensive. I’m looking forward to learning more. Maybe I should call into the Startalk radio show/podcast or a similar one. Maybe a rocketry website can help.