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

So on today's shopping travels, we went by Ollie's where I purchased the following books:

Star Trek: Into Darkness (the novelization)
1944: FDR And The Year That Changes History

And here are the yearly totals:

Feb 1: 5 books for $15.61; average of $3.12 each
Feb 1: 2 books for $22.51, average of $11.26 each
     Total: 7 books for $38.12; average of $5.45 each 
Feb 15: 1 book for $9.10
     Total: 8 books for $47.22, average of $5.90 each
Mar 4: 2 books for $17.52, average of $8.76 
     Total: 10 books for $64.74, average of 6.47 each
Mar ??: 1 book for $10.98
     Total: 11 books for $75.72, average of $6.88 each
Mar 28: 3 books for $10.57, average of $3.52 each
     Total: 14 books for $86.29, average of $6.16 each
Apr 9: 3 books for $40.47, average of $13.49 each
     Total: 17 books for $126.76, average of $7.46 each
Apr 17: 1 book for $9.17
     Total: 18 books for $135.93, average of $7.55 each
Apr 18: 4 books for $11.62, average of $2.91 each
     Total: 22 books for 147.55, average of $6.71 each
Apr 29: 3 books for $22.70, average of $7.57 each
     Total: 25 books for $155.12, average of $6.20 each
May 3: 1 book for $11.02
     Total: 26 books for $166.14, average of $6.39 each
May 15: 2 books for $7.40, average of $3.70 each
     Tota: 28 books for $173.54, average of $6.20 each

POLT