Genesis 23

Sarah died.  Abraham doesn't seem very upset--oh, just kidding, he totally mourns for her.  Abraham buys a cave for her burial.  He refuses to accept the cave for free, insists on paying full price for it (so he's not seen as asking for/accepting charity?).  Why was this story considered important enough to be written down and told?  Is Machpelah/Hebron in what would become Israel?