What is the value of a US 1 dollar bill signed by Secretary Joseph Barr?

So-called "Barr notes" (1963 B series $1 bills) are worth no more than other $1 bills of the same time period, about $1.25 in circulated condition and $2 to $4 if uncirculated.

Barr notes have an undeserved reputation for rarity. Because Joseph Barr served as Secretary of the Treasury for less than a month at the end of the Johnson Administration, many people assume they were only printed during that month. In fact, the Treasury frequently prints bills from a particular series long after the officials shown (the Secretary of the Treasury or US Treasurer) have left office. The 1963 B series continued to be printed during most of 1969, with a total run of nearly half a billionnotes. Many who speculated by hoarding Barr notes were left with piles of paper each worth only a dollar each.