These are pure guesses on my part, but I would guess that 99% of laptops that are sold each year are purchased with 16GB or less RAM and 99% of laptops that have been sold all time have never had their RAM upgraded.

So I would also guess the number of people willing to buy one of these is pretty high. I purchased the MacBook Air and love it. So fast, so quiet. Could I afford it? Yes. But I also typically use a Mac for 5-7 years so I did not consider it overly expensive.