I still buy new CDs. As much as I have embraced streaming, I still like holding physical copies of albums. I still enjoy reading liner notes.
Thrift stores and garage sales are great for picking up tons of CDs for not much money. Much like people used to do with vinyl, I offer $20 or whatever for a case of CDs. If there are a handful of gems amongst the garbage, then I'm happy. And then I take the unwanted down to a used CD store, where they are happy to buy them from me. And usually just exchange for something they have in stock that I want. Everyone is happy.