The Golden Compass by Philip Pullman (His Dark Materials Book 1) — $1.99
https://www.amazon.com/gp/aw/d/B000FC1ICM
The Subtle Knife by Philip Pullman (His Dark Materials Book 2) — $1.99
https://www.amazon.com/gp/aw/d/B000FC1KJS
The Amber Spyglass by Philip Pullman (His Dark Materials Book 3) — $1.99
https://www.amazon.com/gp/aw/d/B000FC1GJW