Australian post has been issuing First Day Covers incorporating a COIN since 1994. They are known as Philatelic Numismatic Covers (P.N.C.s).
Only a relatively small number of P.N.C. issues were made prior to 2005. After this time, issues are averaging about six a year. Some of these P.N.C.s (including the 2000 to 2002 items, as mentioned in the lot description) were released in small numbers, and therefore command high prices.
In the earlier issues, the designs for the special coins were fairly restrained. In the mid-2000s however, some coins have the Queen's Head in gold on the obverse, while also featuring a multi-coloured design on the reverse. The 2006 Dame Edna Everage issue, is a particularly spectacular but slightly outrageous example! We are pleased to report that recent issues are generally much more tasteful!