'Buy' in the Bible

Araunah said, "Why has my lord the king come to his servant?" David said, "To buy your threshing floor, to build an altar to Yahweh, that the plague may be stopped from afflicting the people."

The king said to Araunah, "No; but I will most certainly buy it from you for a price. I will not offer burnt offerings to Yahweh my God which cost me nothing." So David bought the threshing floor and the oxen for fifty shekels of silver.