Collectors occasionally have an opportunity to acquire extremely rare, expensive stamps by choosing an example with some fault (or worse), or a fiscal cancel. But this is always a difficult compromise.
Another option is to look for elusive but at times less expensive Specimen stamps. We recently acquired four early high value stamps with Specimen overprints, each offered at a fraction of the price for an un-overprinted mint copy.
Specimen stamps such as these are highly collectible due to their scarcity and value. The Specimen overprint was used to mark sample copies of issues that were sent to local postal authorities for reference, rather than for postal use. Condition for Specimens can be dreadful, as they were sent out to various Colonial outposts, but these gems are an exception.
Each value in a given issue has the same number of Specimen examples, around 400 for the King George V issues. The printing figure is the same regardless of the scarcity of the underlying stamp.
This makes every Specimen stamp equally scarce, and often prices for Specimen copies of lower values fetch higher prices than more common un-overprinted copies. The situation is reversed for very scarce high value stamps such as those pictured above.
These stamps are an excellent way to acquire a rarity otherwise out of the price range of most collectors.