According to my pastor, who is teaching us Greek using this text, the price at CBD for this volume is quite good. Speaking as a student, I am delighted with the text as it is positively contributing to my study of Greek.
Duff has presented materials in this book a good learning system that suits a teacher and student. The exercises provided after each chapter helps students to practice so well what they have learned. the simple way, with throughly and NT rooted examples given to illustrate the point is remarkable in this book. The use of grammar and adequate vocabulary refreshes the students' and teacher's grammatical skills, not only in Greek but also in English grammar. My students and I enjoy working with this book to help us read the NT text in its original language!