watch it make sure it's not a chinese copy. a dead give away is the touch screen with 4 or 5 icons on the bottom and games in chinese. If the price is too go to be true it usually is. The difference of being locked and unlocked pertains to the carrier. If a phone is locked, it is locked to THAT carrier, same with unlocked. The phone actual functions will be the same. You can unlock it via software downloads but it will lock up again when you update it at a later date. You can test it buy being locked or not buy placing two different sim cards in it and see if they work. example one Tmobil and another at&t