That’s kind of cool. I have a couple of 1890-something shiny silver dollars that a grandparent/great-grandparent stashed away many years ago. I occasionally take them out and marvel at the sounds they make. I sometimes think it would be spiffy to have a coin from ancient Rome or Greece, but it seems as though the cost would be ... daunting. Maybe I’ll have to have a look.
Ancient coins can be very small, like the size of a flattened pea, to about the size of a half dollar. I have one from Alexander The Great that's so small it looks like someone lost a silver filling - cool how old it is but not much to look at.
In general they are made of bronze (dirt cheap), silver (more expensive, still affordable), or gold (expensive). Also, the sharper the detail, the more they fetch. I have a couple that are large, silver, and have moderately good detail still and they might fetch $1500 or so, I think. But most are very affordable.
From the ebay link I shared you can get five or ten coin lots for under $40. You can get a single coin for under $10. Those tend to be smaller and worn. Most of mine are in that range.
If you want one just for the "wow" feeling, there's no reason not to get one, they can be had for not much money.
I sometimes think it would be spiffy to have a coin from ancient Rome or Greece, but it seems as though the cost would be ... daunting. Maybe I’ll have to have a look.
Greek coins, often very beautiful, and coins from Alexander the Great can be had for less than $100 as well. As with anything, the more famous/infamous the Roman emperor will command a higher price. Some emperors ruled for weeks, their coins are great rarities and cost like it.
But even a tatty late Roman empire coin is over 1500 years old—you close your eyes and try to imagine what that coin has seen, what it paid for. It can be money well spent just for that experience.