Those thirty silver coins Judas was supposedly paid for betraying Jesus - How much wealth was that, in that time and place?

For purposes of argument, this answer subsumes the events of the story as written in the Gospel of Matthew.

Several coins are mentioned in the Bible, including the mite given by the poor widow to the collection box, the "give to Caesar what is Caesar's" coin, and the infamous thirty pieces of silver of Judas. The authors of the Bible do not mention exactly what exact coins these were, so ultimately if we want to identify them today, we have to do a bit of guesswork. We have the firmest idea about the actual identity of the 30 pieces of silver paid to Judas for the betrayal of Christ.

All Jews of the day had to pay their Temple tax, and by rule and custom the tax had to be paid with a specific coin, the silver shekel of Tyre. This was a coin originally minted by the Phoenicians that featured the head of Melquart (a Heracles equivalent) on the obverse and an eagle on the reverse. The coin had long been trading currency in the area of the Holy Land. After the conquests of Alexander, the coins were minted by the Seleucid Empire, and later again by the city of Tyre after the Seleucids lost control of the city. By the end of the 1st century BC, the government of the Kingdom of Judea under Herod was minting the coins themselves.

Why exactly the Temple required the shekel of Tyre as payment is lost to history, but at the time of the ministry of Christ, this was the coin that Jews would have paid for their tax. It may have been the ubiquity of the coins in the area, and it may have been their general high standard of purity. Taking the tax only in the Tyrian coins would have made things simple for Temple officials, who wouldn't have needed to weigh or otherwise assay unknown coins from across the Mediterranean world. The moneychangers that Jesus berated were set up outside the Temple specifically to provide Tyrian shekels to those who did not have them (for a price, of course). Given that Judas was paid by Temple officials for his betrayal, the logical conclusion is that he was paid in Tyrian shekels, which would have been available in large numbers to the Temple officials.

So how much silver did Judas get? That's easy. A Tyrian shekel had 14 g of highly pure silver. 30 x 14 is 420 g.

What was it worth? That's hard. 14 g of silver is worth is around $12 at the time I am writing this, so one way to answer the question is that Judas was paid $360 for his betrayal. However, it is really hard to completely gauge ancient buying power compared to our own day. The typical ancient person could go out and buy a horse or a donkey pretty cheaply and easily, whereas a modern American cannot. On the other hand, I have on my desk a flashlight I paid maybe $3 for, but which would have been a priceless miracle in ancient Judaea.

We do have lists of ancient prices from Roman sources, but a convenient way to think of the value of coins is the oft-quoted figure that a single denarius was a day's wage for a soldier or skilled laborer at the time of Augustus Caesar. The denarius of the early Empire was a highly pure silver coin of 3.9 g, or just over 3.5 per Tyrian shekel. Judas would have had around 108 denarii worth of silver, enough for over 3 months of pay for a soldier or skilled laborer. The yearly pay of a private in the US Army is around $21,000 per year, so we can think of 3 months of that coming out to around $5250. A skilled laborer in the private sector would make more, but we are still looking at something on the order of maybe $7500-10000 for the purchasing power of Judas's silver on that scale. These, of course, are rough estimates equivalence.

However we want to value the thirty pieces of silver, it seems likely that they represented a sum of money that a poor man from Judaea in the first century AD was unlikely to have ever seen before. According to Matthew, Jesus was not betrayed cheaply.

Bibliography:

Guide to Biblical Coins, Hendin and Kreindler (2010)

The Shekels of Tyre https://www.coinworld.com/news/world-coins/the-shekels-of-tyre-ancient-today.html

Coinage in the Roman Economy, 300 B.C. to A.D. 700, Harl (1996)