A sacrifice (giving something away) is going to cost you something and will mean more to you than a sacrifice (giving something away) that cost you nothing.
2 Samuel 24:24 ESV
But the king said to Araunah, “No, but I will buy it from you for a price. I will not offer burnt offerings to the Lord my God that cost me nothing.” So David bought the threshing floor and the oxen for fifty shekels of silver.
I love what King David said in this ” I will not offer burnt offerings to the Lord my God that cost me nothing. ”
It made me think and it has challenged me to give God my my BEST and nothing less because HE deserves everything and after all everything already belongs to HIM.