US collectors have been known to pay extra for minor die variations but this relatively rarely bumps up the price of ancients even though the examples are not common. Below is a Constantius II from Antioch mint (AN) with workshop Z (7) cut over H (8). The silver tetradrachm of Ptolemy II is dated year 33 (lambda gamma) with a delta over the gamma making it year 34. The coin is quite worn making the gamma more prominent but I suspect the delta was cut more deeply and just wore off because it was higher. I have not seen another example of either but neither of these was sold to me as what they are so it is quite possible that there are others out there.
Im not a big error person but when I do find something I get a bit excited. When I was looking at one of my Leopold I with a loup I noticed one of the "A"'s looked doubled. Comparing it with other versions online I guess it was a doubling. It just amazes me sometimes the rules on U.S./World coins get thrown out with ancients. I guess thats part of the appeal for some.
Probably nothing or very little. Everything is supply and demand. Very few people care. I have known a couple collectors over the years that sought out such things but they usually paid according to the condition and this Ptolemy coin is not great. The Constantius II is a decent coin but next to no one collects minutia on latte Romans so to get a bump in price would require an auction attended by two people who wanted that coin. The difference between these an modern coins is modern collectors have to look very closely to find any difference however minor if they want a 'variety'. Ancients are nothing but varieties and no one has any hope or desire to get the complete set. If you want an MS65 US overdate all you have to do is write a check to one of several specialist dealers. If you want either one of these coins, you might have to look a while but when you found one you would be able to pay from petty cash.
Thanks I could easily imagine they amount of types/varieties of coin, say of Constantius II, easily filling up a book and still not being complete. But many ancient collectors seem to look out more for die matchs rather than minor variations; which in a way, may be the equilant of us collectors looking for varieties. It can be cool to find die matchs. I have found die matchs of a couple of my coins(none for sale though), and that denarius of Severus you have. (sorry to go off topic)
