Have you listened to the system? You might be amazed by the involvement with music you perhaps never experienced, and keep some or all of it. It was my inheritance of a remarkable sound system in 1973, age 25, that opened my ears to a lifetime of enjoyment.
I have sold both equipment and reel to reel tapes on eBay,
To get more $, do all you can to identify the piece's specifics now, so you can properly describe them when selling. Good photos now to post for help identifying. Those good photos will be needed to list them for sale later. USA gives 12 free photos for each item you list.
You will do better selling individual pieces rather than a 'system'.
Local pickup is the easiest, but will limit your customers a lot. Selling only in your country is easier, perhaps those brands are better known in your country, but selling international is the best way to reach someone who both knows and wants something you have.
Don't forget, you will pay between 13-15% fees to eBay/Paypal (USA rates) when setting your starting price. And, eBay charges fees on shipping cost, and now charges taxes in USA, even on used equipment.
Shipping costs, local or International: Estimate the size of boxes with protection, and the weight, and pre-price shipping costs to a destination in your country, and pick an average shipping for international shipping. USA has separate prices for country zones, I determine an average, and add 20% for fees and taxes.
eBay USA has arrangements with both UPS and Fed Ex which, if you join their arrangement reduces the shipping cost a lot. This helps you list lower shipping costs which can make a difference when a buyer considers their final price.
I give unconditional returns, buyer pays return shipping, that definitely widens your customer base for used equipment (another reason for you to set it up and listen, verify it works. I have never had a return.