Collectors do more to preserve these things, and to understand the history behind them than any museum, we know what we know about the history of these items, (fine details like who made them, where they were made, how to spot fakes, etc....) because of the research done by collectors. I know people who have found named items, and tracked down the entire story of the man behind them, I've personally researched a WW1 victory medal from the South African Field Artillery, learned the mans life story, and returned the medal to his family. Museums do not do that. The market for these items reflects different interests between different collectors, and an opportunity for those who are not nterested in the items to put them in the hands of someone who does, while making a few bucks in the process. It's better to have historic items like these being sold to collectors than it is to have them destroyed or thrown in the garbage and lost forever. And items like this one, are not going to be displayed in a museum, they will end up in a box or a drawer somewhere never to be seen again.
I've actually had the WW2 Museum tell me they weren't interested in some items simply because I had no background information on them, they said I was welcome to donate them, but they would just end up in storage and never be seen by the public. I think selling those items to someone who will care about them and display them makes more sense
