If you don't believe me about the cheap iTunes, go to this site:
http://itunesvouchers.co.uk/ .
27 GBP for a 100 GBP card. 100 GBP gets you 125 songs. 27 GBP is approximately $54.
54/125 ~ 44 cents a song.
I have bought 4 of them so far. You used to be able to do a buy 1 get 1 free and they work fine.
And yes, there is a way to convert the songs to mp3.