First, some background info: star notes are printed in different quantities than regular notes. A run of 3.2 million star notes is considered a full run, and aren't particularly rare. For modern star notes, 640,000 or fewer notes in a run is typically the starting point for considering it rare.

Regular (non-star) notes are printed in far greater quantities than star notes. It is common for 96 million notes to be printed in a single month - that's an entire block (for example: A 00 000 001 B - A 96 000 000 B).

There have been a few non-star note printings that are a lot smaller than normal:

$2 - Series 2013

Printed June 2016

A 00 000 001 A - A 06 400 000 A
C 00 000 001 A - C 06 400 000 A
D 00 000 001 A - D 06 400 000 A

Printed July 2016

H 00 000 001 A - H 06 400 000 A
I 00 000 001 A - I 06 400 000 A
J 00 000 001 A - J 06 400 000 A

What makes these non-star notes potentially rare and valuable? They are the first and only runs in their respective FRB districts, and they are only 6.4 million notes each. If no more $2 bills are printed for series 2013, these six districts will have a significantly lower quantity released than most FRB's/block combos.

This is entirely speculative at this point, though. If the BEP prints more notes for the $2 2013 AA, CA, DA, etc. FRB/Block combinations, they will become as common as a normal circulation note. Long story short, if you find a uncirculated examples of any of these notes, it wouldn't hurt to hold on to it until we see if more will be printed.