It is interesting to see how much stamp knowledge reaches those who are not really into the hobby. There are those aware enough of some of the rarities that they will swear they have one, even though 99.99 percent of the time it turns out to be something else, either a similar stamp or a reprint.
With all the stamp reproductions around today, thanks to the simplicity of printing with computer and printer, somewhere down the line there is going to be plenty of work for expertisers. And it's not just stamps - replicas of classic covers, only take a few cents worth of paper and ink, with a stamp image in the public domain and historically accurate postal markings and cancellations, to create remarkably realistic philatelic items that are 100 percent fake.
While reputable stamp dealers will have nothing to do with such items, the fakes are available online, where they are sold with auction sites' blessings. While they must be sold as what they are - fakes - problems can arise later when the last buyer decides to pull a fast one and sell a fake rare cover for big bucks.