I find it hard to believe anyone needs 16gb of ram, are you actually maxing it out with your current 8gb? Activity monitor allows you to check i have 16gb in my rMBP and run parallels all day and still would be fine with 8
I find it hard to believe that people probably said the same thing about 2 gigs of RAM back in the day and still are naive enough to think that nobody will ever need more than 8 gb. Or are you short sighted enough to not realize the guy might want to use that computer for the next 4-5 years, can you imagine how much RAM future operating systems and software will require? A computer with 8 GB that can't be upgraded will be obsolete in no time.
I had 4 GB on my 2010 MBP and with just Safari open on a clean install of Mountain Lion, I got tons of page outs. I had to go to 8 GB of RAM.
Why be an apologist for Apple? If the guy wants more RAM, why argue against it? RAM is one thing where you truly can't have enough, and I too think it's bogus you can't get a 13" retina with 16 GB. Hopefully later today we can, but I doubt it.
And no, my wife isn't interested in the bulky classic with the 2008 screen on it.