Computer Systems: A Programmer's Perspective - $70 (Bookstore Price: $79.50)
Condition: Like New

The C Programming Language - $35 (Amazon Price: $44.41)
Condition: Very Good - only slight wear on corners
** This book is an optional book, but very useful on exams/assignments/labs for quick reference.

If you buy both, I'll take off $5 from the total. :)