Thank you for reading my post (from many, many years ago 😎).
Yes, you are correct to have concerns about forgeries.
That said, there are many honest sellers in the market. When buying a coin from them, one could be fairly certain that the coin is authentic. There would be no need to get the coin certified by a service such as NGC Ancients.
Here is an excellent site with both excellent numismatic information and authenticate coins for sell:
https://www.forumancientcoins.com/
One of the coins shown in my post above is in a plastic holder. It was certified by NGC Ancients. The decision whether to get ancient coins certified by NGC is one of the controversies of coin collecting. Personally, I am not a coin collector. Despite looking at ancient coins for more than a quarter century, I am not always good at determining authenticity. Also, buying coins online can be fraught with danger. If I were to buy a coin online, especially from an unknown online seller, I would be comforted by a certification of authenticity from NGC.
A final word of advice, remember that ancient coins are frequently less expensive than a novice would imagine. Please check comparable prices on the market before buying any coin. The site above (Forvm Ancient Coins) has many excellent coins offered for sell by coin dealers who are held to a high standard of numismatic ethics. They are possibly little more expensive, but overall, they offer reasonable prices for ancient coins.
A good site to do coin research or enjoy coin discussion is below:
https://www.cointalk.com/forums/ancients/
If you have any questions, you can send me a message. Good luck.
guy also known as gaius