i have the 64 mb rca k@zoo for 80 dollars U.S., it holds a little over an hours worth of music, uses two triple A's, and sucks up batteries pretty quickly. an excellent buy.
i used to have the RIO *something*, which costed 100 bucks. it took one double A batterie, played the music nice and loudly, showed the name of the song and band, and didnt run out of juice fast at all. then one day it just stopped working. probably because i put the song 'the stroak' on there.