Inflation factors during the Civil War and an indication of relative wages in the 1860s.

An insightful indicator of wages during the Civil War can be found in The Cause Lost: Myths and Realities of the Confederacy, by William C. Davis. Book also has useful indicators of inflation through 1863.
The northern economy was quite strong during the Civil War, with demand for skilled and unskilled workers in industry creating more lucrative job opportunities in the civilian world than being in the army.
While the pay for a soldier was $13 a month, the author says a man could make four times that much money merely by working as “a sign maker or a clerk in a dry goods store” (location 26210). That stat is credited to American Annual Cyclopedia, 1863, p. 413. A 30 second search on the ol’ internet suggests the book can be had for between $60 and $100.
The ratio of 4x suggests a dry good store clerk could make somewhere around $50 a month.