I'm sure the x6500h will go on sale. But check out the new AVRs. Denon is going to be pushing out some cool new features that you might interested in. New HDMI 2.1, 8k, etc...
I would say 50% off would be a great deal! Haha. Are you in the USA or another country? For in-walls, if you can find something around the $1k/per speaker, you'll be in good hands. B&W, KEF, Martin Logan, Paradigm, RBH. Just to name a few.
Yeah, stay away from Klipsch subs. They are not that great. I think you can get two SVS PB2000's for $1200. That would be a better option.