yeah I get bad packaging alot but I typically buy such fucked up equipment that I do them a favor and don't complain because if its on ebay
1) i am already getting a deal
2) its going to be alot of work to repair it, fighitng with back and forth shipping might just cause worse damage
3) given all the other repairs that need to be done a bit of a glue job is no problem (invest in a good plastic glue system, i.e. DP8810, Loctite Prism, plastic sensitizer
Then you are only left with problems on small parts that crack where the tensile strength of the glue does not compare to the original part, but typically that's cheap. Half the time I know I am lucky that the seller even shipped it for the price I get, so I don't complain unless its totally broken like a chip thats cracked in half. Like I got a bad banana jack on a lab amp, but on the other hand, I ended up taking it apart because it was cracked and lubricating the switches and cleaning it up and all this kinda stuff I might not have done, and I found a problem I would have missed!
Some people try to run ebay like you are doing purchasing for a high end aerospace company (note I said high end), but with 60 year old equipment and prices penny on the dollar. Give it a rest, it will never happen unless you run into those mad men with a injection foam machine or something like that. Even they don't really care unless its like.. going to the military

And most of the time it pays off if its damaged because if I bend a shitty chassis back into shape, I might as well paint it instead of having another mangey cow boat anchor around.
Thankfully they put the ASIC's deep into the unit so they are usually fine (what you are paying for). And you get more education when you fix it anyway, so its wortwhile.
When I consider the normal service hours number required to bring old gear back into good shape, the extra repair is usually less then 10%. And half the time the part was in such bad shape that your just basically getting a free stress test from the mail man to remove bad system elements (fighting over a rotten banana jack for instance!)
My super duper tip: if you sell equipment, get another piece of styrofoam and poke holes in it and tape it over your switches and shit, even if the gear is sent wrapped in a paper bag it will likely survive OK then. Id prefer that to ineffective bubble wrap to be honest. Most of the time its packed with high quality bubble wrap *unnecessarily good* but the stuff in front is not protected, that is the important part.
Better then a real supplier sending you nicely packed loose pliers (jesus!)