Sony doesn't really do black friday pricing on sets much, especially something like the 900E. You can take the risk and not buy now and hope it will be cheaper but no guarantees. Last years sets barely dropped in price. Usually Samsung discounts heavily since they don't have set pricing or LG which tries to increase OLED sales and then increases them again.
As for the discussion above, I honestly don't know what tv O/S you guys think won't give you the same issues you're having with Android TV beyond o/s sluggishness. I have to restart my KS8000 almost daily, close youtube and netflix several times on Tizen. For Android, the only issue I really have if WiFi disconnects and just the stupid slowdown due to it being displayed and loaded like a tablet o/s on a television. I even have built in ads now on the KS8000 menu row. I cannot disable anything, cannot stop data collection like I can on Android o/s.
I will give you that the remote is generally poor. It isn't even the SoC or processor or storage. They are much head of what the KS8000 has. It is just the design and footprint of Android TV which has been a google afterthought. Very poor start screen, bloated, sluggish.