Alan, I've "liked" your post, but I wanted to write you to thank you. When I get tired of my generation 3 -- that is, when I want to resume taking long trips in the car -- I will test-drive the Ioniq and the Prius, and see what I think. I'm almost sure the Prius will be more expensive, but it may be worthwhile. Despite my gripes with Toyota, I know the cars are generally quite reliable, and I value that a lot.
So, did you check with Todd, yet? Here's what he has as of today. I see several possibilities, but no Gen 4s in stock. Listings - Tampa Hybrids Inc.
You can get into a 4th gen now for about 14k if you shop around. Have seen some dealers asking $14,500 sitting on the lot. Privately, even less. A bit of negotiating will bring it down, and possibly a few bucks for your used up nissan might be able to get it into the 12's. Here is a dealer with a 2016 and 88k miles asking $14,500. Carfax looks ok too. (no accidents/damage reported) Used 2016 Toyota Prius Two for sale in Chesapeake, VA 23320: Hatchback Details - 483594549 - Autotrader