Dr.Dre Monster Beats Studio Metallic Blue with ControlTalk ?

Hi im selling my used but basically brand new Monster Beat Studios, they have only been used about 3 times and packed back away in the box. When I went to use them last they would not turn on, I tried some different batterys but they didnt work (plus I dont even know if the batterys work). They still come wrapped as new, still have the original box and sleeve, the cables, jack adaptors, carry case and instructions. They cost 349.99 when I bought them, I have no idea what could be wrong with them and as I hardly used them I wont spend the time trying to repair them.