I gotta send my shot out to Nero, and yes you can buy it without a burner, I've even seen it a a Staples.
Also if you just want to burn mp3 files definitly give a look at Feurio, its just for MP3's and works great. Plus you can use it for free with some Popups(not spyware) to ask you to register as you are getting ready to burn, but just push close.