You should be able to use your own ringtones with Android phones. You should be able to download applications such as MyXer which will allow you to download them for free. If you have MP3 files, there are applications you can install that will make them into ringtones.

Or did they lock that custom ringtone adding feature? Just like Boost Mobile did saying "You have to buy our ringtones" I mean come on I made my own and have 25k ringtones at the moment.