Hi,
As a volounteer lookerupper on both genesreunied and RootsChat, specialising in Gloucestershire and the NBI is a valuable tool. After all, we all know the difficulty in finding burial plots. I find the NBI an invaluable, but due to copyright restrictions I am not allowed to publish their data openly on RootsChat. Having exhausted my own family tree I enjoy trying to pass my experience onto others.
Go onto the Federation of Family History Societies website and you can purchase a copy of the NBI, Third Edition. It's rumoured that it won't be published again due to royalty problems! I paid 40 quid for my copy sometime ago. You could, also, by a copy on Ebay or many other websites.
Victor