Are You Betraying Your Friends?

Bilbo offers Thorin the Arkenstone of Thrain. He says, this is the most important thing for Thorin. This will help you negotiate with him. And they say, how can you give this to us? It's not yours. Bilbo: "They told me that number one, they told me I could choose anything I want" So basically what Bilbo is saying is he's saying, I will give you my money.