I’ve often wanted to do that (ancient coins) but alas, no cash. :^)
I’ve gotten some ancients for $3 or $4. I picked up a Marc Antony silver coin, very worn but still identifiable for $20. I have a large Nero bronze that I paid $25 for. And it is just as old as an example costing thousands. Very decent third and fourth century Roman bronze coins can be had for around $5. When I got into it, I spent a lot more money on books for research than on coins. Now there are really good internet sites that will help you track down info on your coin. And I find that’s a big part of the fun of the hobby.
If you live near a big city look for coin shows and if you’re lucky, there will be dealers who deal in ancients. Some will even have a ‘take your pick for $5’ box. It is really a fairly cheap way to get authentic ancient art (especially the Greek coins).