American Book Company’s Classified Textbook Prices, 1915. $1.00 in 1915 = $21.80 in 2011.
Most Expensive Textbook: Church’s Descriptive Geometry, etc. (2 vols) $2.50 ($54.51 in 2011 $)
New University Algebra. With Answers $1.58 ($34.44) , Key to the same $1.50 ($32.70)