After King David made a huge mistake with his authority, ordering his followers to do something wrong, he was reconciled to God, and sought to celebrate that reconciliation by consecrating/commemorating the place where it happened.
The owner of the property, a man named Araunah, offered the sizable piece of land to David – for free!
But King David said to Araunah, “No, I insist on buying it for the full price. I will not take what is yours and give it to the Lord. I will not present burnt offerings that have cost me nothing!”
(1 Chronicles 21:24, New Living Translation)
You see, a sacrifice that costs you nothing personally is not a sacrifice at all.
Or, to put it another way –
Jesus sat down near the collection box in the Temple and watched as the crowds dropped in their money. Many rich people put in large amounts. Then a poor widow came and dropped in two small coins. Jesus called his disciples to him and said, “I tell you the truth, this poor widow has given more than all the others who are making contributions. For they gave a tiny part of their surplus, but she, poor as she is, has given everything she had to live on.”
Mark 12:40-44, New Living Translation)
What are you bringing before the Lord?