I've got books lining my shelves, day and night...

Over the weekend, I found myself in a Barnes&Noble.  Therein, I purchased two books:

Star Wars Super Graphic, by Tim Leong
After The Civil War, by James Robertson.

Here are the yearly totals:  

Jan 21: 2 books for $5.26, average of $2.63 per book
Jan 26: 2 books for $21.14, average of $10.57 per book
     Total: 4 books for $26.40, average of $6.60 per book
Feb 20: 2 books for $14.57, average of $7.29 per book
     Total: 6 books for $40.97, average of $6.83 per book
Feb 25: 5 books for $18.22, average of $3.64 per book
     Total: 11 books for $59.19, average of $5.38 per book
Mar 11: 3 books for $11.83, average of $3.94 per book
     Total: 14 books for $71.02, average of $5.07 per book
Mar 22: 3 books for $15.12, average of $5.04 per book
     Total: 17 books for $86.14, average of $5.07 per book
Apr 11: 2 bucks for $33.37, average of $16.94 per book
     Total: 19 books for $119.51, average of $6.29 per book
Apr 28: 6 books for $37.74, average of $6.29 per book
     Total: 25 books for $157.25, average of $6.29 per book
May 12: 1 book for $8.84
     Total: 26 books for $166.09, average of $$6.39 per book
May 14: 4 books for 13.74, average of $3.44
     Total: 30 books for 179.83, average of $5.99 per book
July 15: 4 books for $22.66, average of $5.67 per book
     Total: 34 books for $202.49, average of $5.96 per book
July 16: 6 books for $86.72, average of $14.45 per book
     Total: 40 books for $289.21, average of $7.23 per book
Aug 5: 2 books for $27.41, average of $13.71 per book
     Total 42 books for $316.62, average of $7.54 per book

POLT