What you are witnessing in this Scripture is a very subtle land deal that takes place without either side wanting anyone to think that they really want it done. Abraham insists that he pay for the land to bury his wife Sarah. This makes sense because he never wants people to think that it was a result of their favor that Abraham increased in wealth, but rather that it was a result of God’ favor that Abraham increases. Well, the Hittite is placed in a difficult position because Abraham is well liked and is grieving the death of his wife so no one would want to be seen as taking advantage of him in his time of grief. He offers the land for free. Abraham refuses. Notice what happens next, the Hittite sets a price by saying: “What is land worth 44 sheckels of silver between the two of us?” He again encourages him to take it for free. After having said that, it is clear that the price was set for 400 pieces of silver.
The fact that Sarah dies gets somewhat lost in the whole story of this land deal. My guess is that this Scripture is so clear that Abraham bought this land from the Hittites that in later years when the land would be contested, and it was always contested, they could point back to this deal which was done in the presence of all the people in the principal square of the land. This Scripture serves to inform us of Sarah’s death, but serves primarily to set a marker in history for that piece of land.