This. All of my headphones are used. We are in a hobby where people generally take care of their stuff and phones cameras mean everyone can take high quality pictures. Always make sure to ask about the condition and then always pay with paypal goods and services. Typically headphones take a massive hit once they are no longer new in the ball park of 50-80% but after that as long as they are well maintained the value stays pretty flat for quite some time. So as long as you are patient and don’t over pay you pretty typically are only out the cost of shipping and the goods and services fee. Then I don’t just get a month but as long as you want to really get to know them.
You should EQ them and they could sound even better.