Because it was but of mean price, and of very common and necessary use in all their sacrifices, Leviticus 2:13 Mark 9:49.
Related Commentaries of Ezra 7:22
Ezra 7:22
22 Unto an hundred talents of silver, and to an hundred measuresc of wheat, and to an hundred baths of wine, and to an hundred baths of oil, and salt without prescribing how much.