Will that even be possible? By that time I'm guessing the battery systems will be worn out and in need of replacement, and who wants a used car that they immediately have to sink $10K into for the special battery pack? And the rest of the electric systems on the car won't be far behind as far as needing replacement due to wear and tear as well.
Time will tell of course, but I'm thinking that an older used Prius will be a hard sell.
That, and the styling doesn't exactly exude virility like the 50's, 60's and 70's muscle cars did....but then I'm a shamelessly biased old stoat ;-)
Even if the batteries are shot, you can still drive it around on the gas engine, just not get as good fuel economy. And those Toyota engines are hard to kill, so I expect you’ll see Priuses soldiering on for decades.