Miss Price said readers got involved in the books and became part of its world.
Part of its appeal was how the books could be read and enjoyed by anyone of any age.
"You can read it to your own kids, and they can read it to their kids, forever."
She was about eight when the first book was released and remembers falling in love from the start.
"I was eagerly awaiting each book as it came out."
The sixth book, Harry Potter and the Half-Blood Prince was her favourite because of its storyline where Harry and his friends started hunting for the horcruxes.
She hoped she would enjoy this book as much, even though it was a play script rather than a novel like the rest.
Bobbie Sendall from Paper Plus Tauranga said people had been waiting at the shop at 11.01am Sunday when the book went on sale.
Yesterday morning, the shop sold 15 of the books and when she arrived at work, there was a list of people that had called to enquire about it.
"Some people didn't even open it so it would be all a surprise when they got home. One girl ummed and ahhed for a long time because as a script, she thought it wouldn't be like the others. But I don't think J.K. Rowling would put her name to something she's not happy with."
