Absalom's good looks get him KILLED
The weight of Absalom's (one of King David's sons) hair, at 200 shekels, was not enough to save him, but rather caused his destruction. This shows us the insufficiency of beauty:
"Now in all Israel there was no one who was praised as much as Absalom for his good looks. From the sole of his foot to the crown of his head there was no blemish in him. And when he cut the hair of his head - at the end of every year he cut it because it was heavy on him - when he cut it, he weighed the hair of his head at TWO HUNDRED shekels according to the king's standard.
"Then Absalom met the servants of David. Absalom rode on a mule. The mule went under the thick boughs of a great terebinth tree, and his head caught in the terebinth; so he was left hanging between heaven and earth . . . And he (Joab, the son of David's sister and commander of David's army) took three spears in his hand and thrust them through Absalom's heart, while he was still alive in the midst of the terebinth tree. " (2Samuel 14:25-26, 18:9, 14)
Two hundred shekels and an idol
Micah's graven image was purchased for 200 shekels, the significance of which led to the introduction of idolatry into Israel and the (possible) blotting out of the Tribe of Dan from the blessing of Revelation 7, showing us the insufficiency of mere religion:
"Now there was a man from the mountains of Ephraim, whose name was Micah . . . Thus he returned the silver to his mother. Then his mother took TWO HUNDRED shekels of silver and gave them to the silversmith, and he made it into a carved image and a molded image; and they were in the house of Micah.
"The man Micah had a shrine, and made an ephod and household idols; and he consecrated one of his sons, who became his priest . . .
"Then the children of Dan set up for themselves the carved image; and Jonathan the son of Gershom, the son of Manasseh, and his sons were priests to the tribe of Dan until the day of the captivity of the land. So they set up for themselves Micah's carved image which he made, all the time that the house of God was in Shiloh." (Judges 17:1, 4-5, 30-31)
Ezra's 200 singers
Ezra's 200 "singing men and women" (Ezra 2:65), were "not sufficient" to produce peace with God, true spiritual worship, or joy in the Lord. Only God's word rightly ministered can lead to this (Nehemiah 8:5-9). This shows the insufficiency of external things in the worship of God, and the impossibility of worshipping God with the senses. True worship, which alone God will accept, must be spiritual (John 4:24).
The Meaning of Numbers: The Number 390
Three hundred ninety represents Israel (Ezekiel 4:5), being 13 x 30; as 65 (5x13) represents the tribe of Ephraim (Isaiah 7:8); as 40 (5x8) represents Judah (Ezekiel 4:6); and 70 (7x10) is the number of Jerusalem.
As a matter of chronology it was 390 years from the division of the Tribes of Israel to the Captivity, and thus the duration of the separate kingdom of Israel was 390 years, as referred to in Ezekiel 4.