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)