If I remember correctly, it can be pretty pricey. I haven't looked in a long time though. Our local book store used to sell a copy before it went out of business. I think they were like $24.99 a volume or something? I can't remember how many volumes, but it sort of put me off a bit

I later downloaded it digitally, but never got around to reading it

Nausicaa being my favorite Miyazaki movie of all time, I'm always interested in it. I might try to hunt it down and see someday again. It will definitely happen. Eventually