This sample, with its elegant scrolled numerals, is not so rare as many of the other pattern pieces.

The Sheldon rarity scale goes something like this:

Rarity 1 - over 1,250 examples known
Rarity 2 - 501 to 1,250 known
Rarity 3 - 201 to 500 known
Rarity 4 - 76 to 200 known
Rarity 5 - 31 to 75 known
Rarity 6 - 13 to 30 known
Rarity 7 - 4 to 12 known
Rarity 8 - 1 to 3 known

The Henry W. Bass collection of pattern pieces in the Money Museum contains mostly Rarity 6 and 7, though, like this gem, there are a few 5's.