Most but not all changes can be retro-added and many of these are not provided without the owner paying. But earlier cars will be cheaper, and all will be low mileage.
I don't know about earlier cars being cheaper. There is simply too much demand, not enough units and copious amounts of drool envy. I have put over 6,000 miles on this since last December and it looks great, many of the issues have been addressed and done under warrantee and all other little niggly details have been done. I have no doubt in my mind that I could sell it at what I paid for it as most everyone I know who is interested are not willing to wait. This is the ultimate impulse buy and waiting 6 months to a year and a half is simply not acceptable to someone with the cash and wants it NOW!