locked means, its locked to a certain sim card, like telstra and the you cant put a differnt one in thats not telstra, if you get me?
and unlocked means you can
your going to have to ask the person y ou buying it from
discuss your questions only with the person your buying from. He is not able to lie about anything. He will tell you everything you want to know or he will never be able to ebay again. Just report him. Its not worth it to him to lie to you.