Jamieson, Fausset and Brown on Jeremiah 32:9

9. seventeen shekels of silver--As the shekel was only 2s. 4d.., the whole would be under £2, a rather small sum, even taking into account the fact of the Chaldean occupation of the land, and the uncertainty of the time when it might come to Jeremiah or his heirs. Perhaps the "seven shekels," which in the Hebrew (see Margin) are distinguished from the "ten pieces of silver," were shekels of gold [Maurer].