I’ve suggested a few times before that you really don't have to buy any new music these days, because you can always (and without much effort) find something interesting somewhere on the Internet.
In an attempt to test if this theory is correct, I did a search this morning and quickly came across the (to me) unknown Chicago based band Fruit Bats.
They play nice and melodic guitar pop/rock and the following 4 songs are available for free download:
Spelled In Bones (Released 2005)
Silent Life (MP3)
Lives Of Crime (MP3 - click listen and choose download)
Mouthfuls (Released 2003)
A Bit Of Wind (MP3)
Slipping through the Sensors (MP3)