At my age, and with my immediate family neither interested in enjoying nor technically competent to maintain an audiophile system, I found estate planning for my system necessary.
First, selling a complete system in an open market will be difficult. If you know an audiophile that likes your system and is willing to make the spend you stand a better chance at a system sale.
Second, my recommendation is to find a local dealer. A very reputable local dealer I have dealt with has experience in high end equipment estate sales and sadly does this for the families of customers who have transitioned a few times a year. He will take the complete system, purchasing some pieces outright and others on consignment. I have left his contact information and specific instructions for my family, including instructions to pay a moving service to package the speakers in their original crates. There also is TMR Audio. I have had good experiences both purchasing and selling equipment from them in the past. It is more of an impersonal process than using the dealer I have experience with.

