What is the best way to get a value/selling price for audio equipment that I would like to sell?

I have a Sherbourn tuner,a Cinenova Grande amp/preamp, McIntosh multi room controller, Sony 400 cd disc changer, pair of Shahanian oblesk speakers etc.

Can someone suggest the best way I can sell these?

Thank you,

You can use "straight line depreciation" over 10 or 15 years unless it has "collector value";  or Internet search for other sales.