Help with virgin mobile cell?

Ok so my virgin mobile phone is, well it sucks but its cheap. haha its a rumor touch and i want to use my "media player" sounds as a ring tone. and im not that bad with phones but i cant get this. cause ringtones are $2.50each and i dont wanna pay that every time i get sick of a song. so any help would be amazingg! and other stuff that might help with virgin mobile. like sites that let me get free stuff or whatever. (ok 2.50 isnt alot, but im 15 with no job.. )