There used to be CD stores and every major outlet had some assortment of CDs. Then they all went online and you could order CDs from all sorts of quant and off colour websites. But that's all gone now, or have escaped me. How do people get there CDs today?
There's Discogs, of course.
In my city there are still record stores that sell second-hand CDs. The great thing about (at least) one of those stores is that they also sell records on Discogs. You can browse through their stuff on there, use the many filters that the Discogs marketplace has, and then simply send the store a e-mail with a list of records you want to pick up at their store. No shipping prices, no online payments.