Playbooks › The Opal-Buying Playbook Image 1 of 1 The Opal-Buying Playbook Sale Price: $27.00 Original Price: $54.00 A practical guide to buying opal. Essential guidance for researching, evaluating, and purchasing opal with confidence. Add To Cart Added! A practical guide to buying opal. Essential guidance for researching, evaluating, and purchasing opal with confidence.