They could do this list one better by making it official.
Make a list of artists that are marginal or low resale value, along with those that nobody is buying, and put it online so that a quick check can tell someone if it is worth it to bring in their old disks for sale or trade.
It would save a lot of time and unhappiness if they knew their stuff was worthless, so didn’t have to be told that by an employee.
For some reason they do seem to have a lot of 2004 "almanacs" for sale though. Who even buys these new?