You know, every old motor suffers when a new one is introduced. Pan to Shovel; Shovel to Evo; Evo to twin cam; twin cam to Milwaukee 8. The '15 and '16's didn't suffer as much to start with the new M8 in 2017 as, say, the Evo did when the twin cam was introduced in 1998 and really broadened in 1999. The Evolution was (and is) a very good motor as is the Twin Cam. Both had issues but "new" is what we consumers like. My '15 was worth around $27K retail last Winter (2018) and, 8 months later, was just below $20K trade. They have it on the showroom for low $20's but I'm betting that is VERY flexible.
In keeping with the subject of this thread, I was patient on waiting for the Indian price but waited too long thinking my Harley would still carry a good trade in value. Nothing wrong with the '15 so I wasn't in that big a hurry but trading when I did cost me money on the trade. However, if I had waiting longer, I would have lost more specially since the 2020 models are just around the corner. By the way, in waiting and being patient on the model I wanted from Indian, I got a significant reduction in the MSRP which helped offset the money I was losing value-wise on my Harley.
I'm happy with the move. With the stage II installed, it's got a lope and sound like an old Shovelhead, rides better than the '15 did even with upgraded suspension. It's getting around 41 MPG around town and got 45.5 on a day trip to Chattanooga a few weeks ago...not too shabby...plus Vickie loves the color (she didn't care for blue) and already says the Chieftain rides better, sounds better and is smoother than the Harley ever was.
If one was looking to either move away from Harley OR purchase a new Harley, end of the model year is one of if not the best time to shop. There are Harley dealers that still have new 2016's on their floor much less new 17, 18 or 19 models. Shopping around does help but developing a relationship with your dealer can also help. I tried to stay loyal to the same dealer here in Knoxville and have (except for the '12 SESG...that one came from SMHD). In doing so, they know me and have worked with me on price. I've always received a discount on clothes and at least 20% on parts on EVERY purchase, not just a few months after I bought a new bike. I got to stay "loyal" with the Chieftain also...the Brown family owns Indian of Knoxville, too, and that helped with the bottom line on trading.