If the product was registered and still under warranty there is no cost for repair or shipping, just go online request a repair and they will e-mail you the shipping label.
Having said that, I sent in my Xbox several weeks ago when it was not reading the discs, after 2 weeks they sent it back and it was freezing and getting 3 red lights right out of the box. So back it went again this time with a priority repair, the Microsoft employee was actually very courteous and apologetic about how that should not have happened.
