As an example, before the days of Bluetooth, I had a classic ipod with 60GB storage, and put all my music on it. But it had to be plugged into a dock, so I've got a few of those, some very expensive such as Bose and Ruark.
Then I bought a wireless Yamaha dock that transmitted the music from the ipod without wires. I was so impressed, I bought 2 more to go in other rooms, so I could hear my music all around the house. They cost over £100 each.
Then along came Bluetooth and they all became redundant and unused, but in total cost at least £3000 including the docks, not the stuff you put into a skip. Then along came fibre broadband and streaming, so all my top-end CD players are now redundant as well, not to mention my top of the range Sony VHS decks. And don't even mention my top of the range cassette players, mini disks, hifi speakers etyc etc, probably cost £30,000 over the years.
I would sell them at a knock-down price to an enthusiast or collector, but don't want to put them in a skip!