TIL that you can get a Roman coin for as little as about $30.

The value of coins might be quite difficult to understand for a non-numismatist. There are some Roman coins that are actually not that rare (more common than several types from the 19th or 20th centuries) that look just like others that are several orders of magnitude more expensive.

Do you know what a ”cheap” pure gold coin costs, if there are such coins?

I don’t know much about Roman coins, but in general cheap coins have the value of the metal they are made of. For more modern coins that’s actually quite common. There are fewer collectors because the coins are so expensive.

From quick look at a seller website you could find some gold Roman coins around €1000, no idea about how prices might vary in the US.

> For more modern coins that’s actually quite common. There are fewer collectors because the coins are so expensive.

FWIW modern gold coins (as in after countries went off of the gold standard) are pretty much only collectors or investment items e.g. the "Eagle" coins stopped being circulation coins in 1933, but since 1986 the US mint started issuing new "bullion" coins. These are legal tender at their face value, but the face value is nowhere near actual value (e.g. the 1oz $50 coin is currently worth about $2000 as gold prices have skyrocketed in the last three years)

Indeed. Some mints even stopped putting a face value on some coins, like the Royal Mint’s Britannias.

Union Latine coins from the 19th century (mostly Swiss, Belgian, and French francs) and some British sovereigns are quite easy to get at metal value (edit: I mention these because they are somewhat old; there are plenty of 20th-century coins in the same situation). They are convenient because everyone (interested) knows how much they weight and therefore how much they are worth, give or take some Greek shenanigans.

Yes. I’ve collected quite a few over the years. Some coins from the later empire are quite affordable due to the mismanagement of the fiscal system during the crisis of the third century.

What you call mismanagement is an inevitability that no amount of "proper management" can solve. If the private sector runs a surplus, the public sector must run a deficit. It's that simple.

I wish money was just a medium of exchange. Nobody needs money to be a store of value. It's a fallacy. We have an entire banking system that already does that part.

Is this due to the cutting of the coin with cheaper metals ?

The usual factors are: it’s less glamorous so there are fewer collectors; we find more hoards from troubled times; debased coins tend to be more common (they would not be debased if there was no need for more coins).

Yes, the coins were heavily debased during this period, which was one of the main causes of the collapse of the Roman Economy during this period. The Antoninianus coin went from around 40% silver to less than 5% silver in a thirty period from the 240's until the 270's. A great number them were minted in the later time period.

Where?

I did just that recently after watching this youtube vid late at night. I was enthralled and opened up ebay and bought one for around $20.

https://www.youtube.com/watch?v=7U77Irq7_qE

Where did you get a Nuka Cola cap, off Etsy or something? Or from the limited run of Jones sodas?