Agree with david99.
If you sell yourself, and not familiar with the items, even with Audiogon Blue Book pricing you will need to determine the condition in order to determine the real value.
Easiest would be to sell to a trustworthy dealer of high end used equipment who would do such an assessment as part of the resale, but you won’t get top dollar with anyone as a middleman. Or someone similar who might help determine condition and associated value from that for a reasonable fee maybe.
I think in any case first step is to determine condition and value reliably somehow.
Ebay with low iniiial bid value will work to get it sold easily for some fair market value based on the information you have and provide.
Also be aware of listing fees, shipping fees including insurance, etc when putting anything large and or valuable up for sale openly.
There are companies that will do proper ebay listings for you as well I believe. Never heard of any doing that for Agon.