I'll just buy off-axis strikes! Writing missing around the edges and stuff. What faker would bother making cheap stuff? I mean I reckon a faker using real silver to make an expensive Denarii is gonna remelt a bad strike!
: ( I nearly bought one just then but they didn't ship to australia. What's with the yellow-looking Denarii? Does anyone know? Some of them look like they've been spray painted with gold-tone yellow! LOL! ie: http://cgi.ebay.com/ACC-Caracalla-A...ltDomain_0&hash=item19c498ed7c#ht_2019wt_1059
But that's a really really good powerful strike! It DOES look a little fake. How-about a worn one which is also off axis?
If you really want to avoid fakes, there really is a brilliant way to do it. Only buy from trusted and repsected dealers and you'll never have to worry about fakes
For every supposed rule I've heard for fakes (like "No one makes fakes of fourees" or "No one would bother making fakes of common coins of Constantius II"), I've found at least one exception. GDJMSP here gave what's probably the best piece of advice you can get for avoiding fakes. To that, I would add that the other important factor is to look at a lot of coins, both real and fake, to get a feel of what coins you want should look like and what signs there are for fakes. Even just by looking at things like VCoins a lot, you'll get a basic feel for how these things should look, and that should help you avoid the lower quality fakes.
The "Black Sea Hoard", probably the largest group of fakes to come onto the market in the last 50 years had offcenter strikes. This was done I believe to make the hoard look real. There is no protection like you say. Think about it, even a badly offcenter coin will still sell for much in excess of any metal content. Its still pure profit. A few years ago they had roman uncleaned coins containing fakes. A dollar a coin is still almost pure profit, and lots of people in the world would love a dollar a coin profit.
There's some areas that are still very safe. Like medoraman said, the black sea hoard is the reason why I don't want to own a Apollonia Facing Gorgoneion drachm. They are very beautiful, but too expensive to buy. That hoard fooled even dealers! As Doug said, buying from reputable dealers is the way to go. That, and getting the experience yourself, which comes over time. http://www.forumancientcoins.com/fakes/index.php that site helped me learn a lot. You just have to be aware of the signs. stainless