I would not presume to comment on much of Zechariah's profound prophecy, couched as it is in language that is mysterious and, I suspect, that has given translators problems in expressing it in English. But this much is fairly clear to any reader from Zechariah 11:12,13 in the KJV :
So they weighed for my price thirty pieces of silver
And the Lord said "Cast it unto the potter : a goodly price that I was prised at of them".
[Young's Literal gives the same sense in reading and differs only in the use of 'Jehovah' as against 'Lord'.]
Here it is quite clear that the Lord himself is conveying to the prophet that it is he, himself - the Lord - who is being assessed or prised at a figure of thirty pieces of silver. There can be no sensible doubt about this.
And the prize, the assessment, is to be 'cast to the potter in the house of the Lord'.
These words were written about 550 years before Judas cast thirty pieces of silver down in the restored temple in Jerusalem and the Jews decided to buy the field of a potter with it, in which to bury strangers, as Matthew reports in Matthew 27:7,8.
Matthew does not mention Zechariah, instead choosing to quote Jeremiah's prophecy, made 650 years before the event, a prophecy which Jeremiah spoke (reports Matthew), but did not necessarily write. For more detail on the apparent discrepancy see such reports as "Answers".
[It is clear from the genealogy written by Matthew that he had access to Jewish documentation other than what is recorded in scripture.]
The other mention of thirty pieces of silver which stands out in scripture is the prescription made, in Exodus 21:28-32, for the decease of someone caused by the goring of an ox. Oxen in scripture are often figurative of those who labour in some kind of ministry, instances of which are too numerous to mention but the law provides, Deuteronomy 25:4, for such in that the ox is not to be muzzled when it treads out the grain and this is referenced in the New Testament, by Paul, regarding ministers, in I Timothy 5:18 :
For the scripture saith "Thou shalt not muzzle the ox when it treadeth out the corn". [KJV]
If a son or a daughter is gored, then the sum of damages is negotiable, Exodus 21:31, but an absolute lower limit is set in respect of servants, which is thirty pieces of silver.
Thus we have a person pierced (gored) by ministers (oxen) and the absolute lower limit for the price of this event is thirty pieces of silver. This is the paltry sum that was offered to Judas for the betrayal of the one who went about doing good - who healed the sick, cleansed lepers, gave sight to the blind and even raised the dead.
A goodly price, says the Lord, via the prophet.
Thus was the Lord prised of those who would crucify him, who would have him nailed to a tree by his hands and feet, thence to be pierced in his side such that blood and water freely poured out.
This is what Israel did to their Lord when he came to visit them.
And it is clear from the prophecies and the allusions already laid out in scripture that he was fully aware of what they would do to him before he came.
A good question to ask; I hope you are satisfied with my answer.