I keep telling him that if he wants real music he will have to go with a single CD player but what he wants is a multiple CD player. Does a beast like this exist? And if so, what is the best one?
I think your advice is a form of audio "snobbery" and puts down your friend who probably likes music and relaxing a lot more than feeding a CD tray (like an assembly line factory worker).
I think your friend can still get "real music" from a megachanger. If he feeds the optical out to a "re-clocker" and DCA or simply a DAC that has excellent jitter reduction capability then there should be no reason why your friend cannot enjoy a large music collection. Alternatively - propose that he burn everything to a hard drive and use a high quality DAC - but to tell him he cannot have "real music" is hyperbole, IMHO.
Besides, the weakest link will still be his speakers even with a Best Buy megachanger...