The four different districts that printed Barr Star notes were very similar and have similar values. A lot of people saved Barr notes and unfortunately for them, the supply outpaces the demand.
If you're patient, you can snag an uncirculated set of all four for under $40. Graded notes bring a little more.
Personally, if found in circulation, I would throw it in a sleeve and keep it or offer it up for face value and a SASE from a new collector.