Usual mp3 encoding rates are 128 and 256kbs, still a far cry from audiophile quality.
Having said that, the type of music you listen to may not make a difference, for example heavy rock or music that has been heavily compressed during production.
Although music CDs have been eclipsed by MPEG technology (for the sake of speed and convenience) the audio quality between the two is undeniable. That also means you'll have to start buying CDs.
If you want more than mid-fi sound, there are a couple of ways to go about it without the cost getting out of hand.
A good quality CD player with an outboard D/A converter, a set of bookshelf speakers and a compact size integrated amplifier would leave a very small footprint in your apartment
A good example(pricey)
Bang&Olufsen
or you can assemble the components yourself, new or used
And then
(my favourite) there's vinyl...