When I sold my Arcam amps I got 2 boxes (one bigger than the other to enable double boxing) from a local storage place, they were only a couple of quid each, but quite sturdy. They obvs weren’t component sized, but they did the job with a load of foam and peanuts.
I do feel there is mileage in a YouTube channel testing the packing potential of various fruits. Pack delicate thing thoroughly in bananas / cherries / apples etc and then expose to the full remit of courier damage techniques, including the “over the fence lob” and the legendary “drop on a corner from 10 feet”, plus as a bonus round “how long does it survive when left under a leaky drainpipe in a thunderstorm”