Greece
The degree of difficulty of a philatelic specialty is determined by three components. First is the intrinsic scarcity of the material, second the cost involved, and third the number of specialized striations into which the field has been separated. Scarcity and cost are related. Scarcity is an intrinsic value related to the amount of material that is available to collectors. It is derived from the numbers that were printed and more importantly the numbers that were saved and have been passed down to stamp collectors. Cost relates to how that intrinsic scarcity interacts with demand. Honduras has many very rare stamps that sell for only a few dollars. Great Britain have many relatively common stamps (such as the Penny Black) that sell for a hundred dollars or more. So cost and scarcity are different factors when considering a specialty. Most want scarcity; not everyone wants costly. And third, the degree of specialization needs to be considered. Each philatelic specialty has a tradition of how in depth it is specialized in. Areas like Germany have literally millions of recognized stamp varieties in the Michel specialized catalog. Areas such as Russia are far less specialized and let the collector concentrate more on getting the basic stamps.