Genesis 23:15

Four hundred shekels. About $116 (see Genesis 20:16). Ephron now named his price, implying that it was a mere trifle for a rich man like Abraham. Although the price appears most reasonable in terms of modern values, in the time of Abraham it must have seemed exorbitant. Babylonian records reveal that average fields were then sold at 4 shekels an acre, and the most fertile gardens at 40 shekels an acre. According to the Babylonian standard Abraham should have been able to buy a field of 100 acres for his money. Though we do not know how large Ephron’s field was, Moses seems to leave the impression that Ephron took advantage of Abraham’s predicament to make a good profit for himself. Otherwise Ephron would not have offered Abraham the field in addition to the cave (see on v. 11).