I never bought an mini disc that already had music, to me the whole point of mini discs was that I could record them, so I always used them to record my CDs and take the mini discs with me. I had a home Mini Disc recorder, a Sony disc man (like a Walk Man) and a 4-MiniDisc changer in my car. To me they sounded very similar to CDs. I still have them but I haven't used them in more than a decade. What kind of music do you like, if I have a CD you like I can burn it on mini disc and send it to you.
If your mini disc is a recorder, you can buy a blank mini disc and record it yourself, it's really simple!