wav to mp3 is what mp3s are all about. Wav music files, as they come from standard CDs, occupy too much space. To solve your out-of-space problem, just convert the wav to mp3.
Quality comes at a premium, especially when you consider that most of the time you'd rather trade a small loss of quality for the possibility of carrying all your albums around with you all the time, or the possibility to keep your entire record/CD collection in your PC without spending a fortune in hard disk space. Well you can do just that by converting the wav to mp3.
By encoding your music files into mp3 format, the mp3 converter software will compress wav to mp3 by discarding small imperceptible frequencies, and will return a much smaller music file with near perfect quality. You won't need to upgrade your hard disks to make space for more music, just convert from wav to mp3, and you'll find a whole lot of space just waiting for you. And what's more: it will cost you NOTHING.