2 Samuel 24:24

24But 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
A  shekel was about 2/5 ounce or 11 grams
of silver.

1 Chronicles 21:24-25

24But King David said to Ornan, “No, but I will buy them for the full price. I will not take for the Lord what is yours, nor offer burnt offerings that cost me nothing.” 25So David paid Ornan b600 shekels
A  shekel was about 2/5 ounce or 11 grams
of gold by weight for the site.
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