Many people have mp3 files on their computer nowadays already. However, there seems to be no natural or easy way to get the mp3s onto MD. MD only takes ATRAC format. And getting the music from CD to MD isn't all that apparent either. On the mp3 players, it would most likely be a straight file copy.
An MD holds 80 minutes; mp3 is 1 MB per minute, and the mainstream mp3 players nowadays are 64 MB or 128 MB. You might ask: they're about the same, and you can carry many MDs if you want. True, but mp3 player storage can be replaced by a CDR, and you can carry many CDR too. I am arguing for mp3 audio player regardless of storage type here.
It doesn't seem to me that the prices of MDs are coming down any time soon. However, if the CDR solution is implemented, or with any other alternative storage that can be shared with a computer, the per unit price of mp3 storage can drop considerably over time.
(The timestamp of this article is an estimated value)