I am sure some, such as this one are valuable of course. BTW he is a fairly handsome guy.
There are a lot of late Roman coins available at reasonable prices $40- $150 in really nice shape. Rougher condition can be had starting at a few dollars.
Price is determined by market forces - supply and demand. Late empire coins are common and though quite collectible not as desirable as coins from the first and second centuries. Of course metal also factors, gold for example. You won't be buying any gold coins for 50 bucks. There are many coins in the high hundreds and into thousands of dollar range. It all depends on what it is and how many people care. But whatever your budget there is some cool stuff waiting to be had.
I used to be a dealer in other fields. I had a gag business card made up for friends - Venal Historica: for the right price you too can own a piece of history.
Some are. Some aren't.
See my post 84.
Late 3rd Century coins are very cheap. Earlier 3rd Century coins are a little more expensive, and much nicer looking, but still very cheap.
This particular one is priceless simply because of its historical rarity.
Go to eBay and type in "Antoninianus" into Search.
This Gordian III Antoninianus is nice.......And still cheap.