I would wish for the 2018's to drop in price like we experienced with the earlier models, but unfortunately that won't be the case. There's a few reasons for the price drops of the 2015 models being the most extreme and best value with newness and low miles:
1. It's the range. I elaborate in a different thread about this, but the idea is that people are demanding EV's with more than 100mi which makes the ones sub 100mi "poop" in their eyes. The new end of the year 2018 models will have 150mi range on just the battery and that hits the sweet spot for people in the know and completely out of the know as far as EV's are concerned. People will be a LOT less likely and a LOT less in a hurry to get rid of their 150mi range i3's compared to their 81mi range ones.
2. Also with pricing expectancy to be higher on the 2018's, people will feel a bigger loss if they sold (and will therefore be more likely to hold onto them) it which will lead again to lower inventory of used 2018 i3's compared to used 2015 ones.
3. Because electric cars are still considered new technology (hasn't been around long enough to see a number of batteries fail), many people who have never leased a car before lease EV's. This led to a ton of lease returns on the 2015 i3's. As people get more comfortable with electric vehicles and a particular model, they won't be as scared into leasing and therefore the inventory of lease returns will be a lot fewer.
If you're waiting for a deal, you can buy the 2018 model in 2021. In other words, if you know you're going to get it for sure and don't mind waiting, It'll be a deal but it'll be nothing like the deals we see now with the 2015 models here in early 2018.
I've seen a 2014 i3 REX with all the packages sell for under $15k with 46 miles on it. That's high mileage and 2014 is too close to nearing the warranty period ending. Although it's super cheap, the value isn't as good as a 2015 for a few thousand more which buys you a car with fewer miles and a longer warranty, plus a car that doesn't have the bugs of the first edition 2014 model. 2015 really is the sweet spot. So if you're going to get one, look and buy. I can help. Just reach out.
The only reason I got a 2016 was b/c it was a rare one produced only between April and June of that year that had the Deka World interior (which wasn't released officially into mass product until 2017 models) and mileage on mine second hand was super low at just shy of 13k miles. if it wasn't for my love of the Deka World interior, I would've gotten a 2015 i3 Rex for sure. It's the best deal out there right now if you know you want an i3. No matter how good the deal is, you should turn away if the i3 isn't for you. Don't waste your money on something you don't really want just b/c it's a good deal.
A fanatic of all things electric. Ridables like electric ice chests and stand up scooters I adore. Drones like DJI, I root for. I'm a fan of both, but nothing beats my love for my 2016 i3 Rex with Deka World. Shhh, don't tell my wife.