Here's some other telling graphs. First one is Millennium Falcon. In my opinion, what's interesting about it is right around the point that it was announced that there would be a "new lego MF" for Rogue One is the point where it plateaued, and then slowly plateaued in price and went south a bit. So, I think the At-AT will continue rising until that new announcement, whenever that maybe. Until then ride the wave.
The second is the trajectory of the OT x-wing, which is still having an upwards swing. It's tough to say if a new x-wing is coming for Rogue One, but it's in the film, so I suspect we might see one, and that will probably plateau that set too. Interesting that Poe's X-wing had no effect on this older version, compared to say the new MF having an effect on the OT MF.
Finally, growth of the Republic Gunship, AT-TE, and AT-TP. All these sets are showing upwards trajectories. So, i'm going to go out on that limb again and say AT-AT's are going to continue to rise. Also, sets that aren't currently retired but getting closer like the Imperial Shuttle Tydirium, Jedi Duel, and all of those first wave Force Awakens sets will probably see those EOL spikes. Granted, not all sets spike like they do as the MF did, as some like the RG, AT-TE, etc slowly but steadily rise in price through the months. But I think we will definitely see good spikes this year with other sets.. Now we just play the "when will the announcment be with a new At-At?" In my opinion, you have to sell right before that announcement to hit the peak. Because then it will more than likely plateau and start a slow but not too steep decline in price, similar to the OT falcon.