No it doesn't cost anything. You can get it by taking your phone to a Sprint store service center or by calling *2 and asking a rep to be flagged for an over the air PRL update. Then once they flag your account you can call *2 back, press 1 for english and the update should start to work. You don't necessarily need a PRL update as it won't affect your phone's performance on the Sprint network. However sometimes roaming agreements are changed or added that you can benefit from. But even that's rare.
