All books are 50% off at the Book Stack on the first floor of the University of Denver’s Mary Reed Building. The volunteer-run Book Stack sells new, used, and rare books on a variety of topics and is considered one of the best used bookstores in the city. This year, the shop has many new children’s and teacher’s aid books, too. Most books are priced from $2 to $4. Some books will be sold for $3 per bag. There are more than 35,000 used, new and rare books in over 90 subjects, including history, psychology, travel, foreign language titles, crafts, fiction, and many more. The sale runs Friday & Saturday, October 14 & 15 from 10 a.m. to 3 p.m. The Book Stack store is at 2199 S. University Blvd. (at Warren), Denver.