Not as severe as in US coins, but there always have been massive spikes because of condition in coins. Maybe hundreds exist in F, but 2 exist in XF. Some collectors just HAVE to have the very best, and compete with others with the same mindset. Good for them, as all collectors I view as brothers, but giving my habit of buying a LOT of coins I cannot afford that viewpoint. I pay up for some coins dear to me, like my avatar, but others not as persnickety.
As an addendum to Agricantus's post I got this Trajan denarius for 230 British pounds ( now 301 U.S. ) Ttajan Ar denarius Rv Statue of Hercules standing on a low plinth. It has a bit of extra value to me as it it is plated in Woytek's book on Trajan. Woytek 164 a RIC 79 3.02 grams 18mm Photo by W. Hansen It actually still has its find patina so it is a gun metal grey in color.
The Trajan denarius above is in very attractive condition. It has a somewhat strange appearance, though. I guess there is no doubt about it being genuine, especially with this provenance? I guess what I'm saying is that if I had seen this coin on Ebay, I would have doubted its authenticity, but obviously I'm wrong.