What Can Be Done: Prussia was the main component state of the German federation that united in 1871. It was Prussian pressure on the rest of the German states that caused Germany to become one country. The reason for Germany uniting was to have the geopolitical heft to compete with the rest of Europe. But the way most Europeans saw it - Prussia was Germany. It is for this reason that the philately of Prussia is so interesting.
Prussia issued 27 different stamps. None of them are rare, as the active commercial economy of Prussia necessitated much postal communications. Prussian post offices encouraged the use of postage stamps whereas some of the smaller German states did not. This means that a plentiful supply of Prussian stamps have reached collector hands. Many Prussian stamps were remaindered out after the stamps were demonetized after Prussia joined the German confederation. Most of the stamps of Prussia were printed by engraving, which make for fine impressions and mean that there are very few counterfeits of these stamps for collectors to worry about. There are even a couple stamps that were printed in reverse on goat beater skin paper- a translucent paper that was used experimentally as an anti-counterfeiting measure (counterfeiters would have trouble getting the paper and the design of the stamp would be damaged when the stamp was soaked off the envelope making cleaning and re use impossible as well).
Completing Prussia is not difficult or expensive, costing in the range of $250. Specialists look for covers and multiples (blocks and pairs). The stamps are well designed and executed. Prussia makes an excellent entry point to both German states philately or nineteenth century specialized philately in general.
Specialty Catalogs: The Michel catalog is used by advanced specialists, but most serious American collectors of Prussian stamps use the Scott Classic catalog.
Specialty Albums: The Scott specialty series is very good, but because so many Prussian specialists collect more than just one stamp of each issue, many collectors make their own pages and albums.
Availability of Material: Prussia is actively collected and has a large dealer network and many offerings. It is easy to complete and specialize in.
Expense: Because of the level of commerce and wealth in Prussia and the relatively small number of stamps issued, Prussian stamps are plentiful. Prussia is one of the least expensive major countries to complete.
Overall Grade: B+