see, that's where you go wrong with this...
if it's radio music, the sad and pathetic reality is that it's more like they're functionally upsampling a master done at 22 khz, 8 bit - so your mp3 compression isn't degrading the sound nearly as much as you imagine that it is.
any artist that's actually taking advantage of cd quality audio isn't going to compress to mp3 well at all...