Banknote age influences collectability due to the following factors:

Newer notes are much easier to obtain, and usually required to be perfect condition to hold a premium in value.

Older notes are much harder to obtain due to being removed from circulation, or possible damage from general wear and tear make perfect condition notes even more sought after.

This note type is a General Prefix.

First & Last prefix notes are generally the most sought after, General prefix notes are less collectable and usually require additional traits such as a low printrun or special serial number to hold a premium.

Additional note types such as Commemorative notes, Test notes, NPA Issued notes, Star Prefixes etc also add to the overall desirability of the note.

A Full print run is generally considered 1 million notes, with new generation notes having the capacity of 10 million notes, lower print runs are harder to come by and tend to compound the desirability of other traits such as First & Last Prefix notes.

The rarer a special serial type is, the more likely it is to attract a premium in the note value, however not all special serial types attact a premium in value.

Special types that do not attract a premium may still increase the desirability of the note when found in conjunction with other collectable factors, compared to similar notes without the special type.