Google and/or FleaBay are your friend, my friend...
Receiver retail $3K new. Worth maybe $400 on a good day.
All receivers lose most of their value a week after they are sold. Your s discontinued, and does not have the latest HDMI, so it is just old junk.
Polk speakers are 12 years old..
For sale $850.
So for all of the stuff, say $1,500 to someone eager to buy.
Which may never happen.
If you got $1,200 for all of it. Take it and run.