A piece of land worth 400 shekels of silver, what is that between you and me?

[TonyChanYT]

After Sarah died, Abraham needed a burial place. He was interested in a piece of property of Ephron the Hittite, Genesis 23:

14Ephron answered Abraham, 15“My lord, listen to me: a piece of land worth four hundred shekels of silver, what is that between you and me? Bury your dead.” 16 Abraham listened to Ephron, and Abraham weighed out for Ephron the silver that he had named in the hearing of the Hittites, four hundred shekels of silver, according to the weights current among the merchants.

Jeremiah 32:

9 I bought the field at Anathoth from Hanamel my cousin, and weighed out the money to him, seventeen shekels of silver.

Cambridge Bible for Schools and Colleges:

In 2 Samuel 24:24 David buys the threshing-floor and the oxen of Araunah for 50 shekels of silver. In the Code of Hammurabi a hireling would not receive more than I shekel a month as wages
Ephron has mentioned a full price; he is poor, Abraham rich: the figure could not possibly be a hindrance to the bargain. The important thing is that he, the owner, is willing to sell. Abraham will, therefore, of course purchase.

Abraham got more than just a field, Genesis 23:

17 So Ephron’s field in Machpelah near Mamre—both the field and the cave in it, and all the trees within the borders of the field—was deeded

Still, it was likely overpriced. Given the circumstances, Abraham accepted the deal and didn't try to beat it down.