
darkstar:
There are many. Some examples are Crash Landing on You, Bloody Romance, Eternal Love, Rookie Historian, and several others. The MP3 files available online are not nearly good as CDs.
Which stores sell those disks?
So I've not used the following but I know the top one has some pretty good reviews on reddit:
I've used Prestomusic.com Personally, I've only used it for digital downloads but I know they also do CDs.
Major retailers, book stores, and tech stores will often have a CD section. You might need to get a specific CD requested to your local location though. This is what I would recommend. If you go CD thrifting you'll sometimes find soundtracks that way, but that's obviously going to be hit or miss and requires you enjoying the process of thrifting itself, which is much more fun if you live in/near a city. (Recently went thrifting and found the Chicago soundtrack on CD!) You can also check your local library. They will sometimes have soundtrack CDs, and if they don't you can also request that they purchase one for you to check out.
For some reason I always have a hard time finding CD retailers for Chinese dramas. Japanese retailers are usually pretty easy to find instead, but the problem is not all of them will ship outside of Japan. For cdramas you might be better off buying off ebay or finding a courier who will ship it out to you. There are some couriers that can be found on etsy or specialty websites. Tumblr has some pockets of courier networks for K-anime but that's about as much as I know in that regard.
Just watch out for resellers who are trying to charge $200USD for stuff. Those are no good.