If the only options for categorizing the Bible are fiction or non-fiction, there's no rational basis on which to decide where to put it, because it has major elements of both in it. Many of the people, places, and events it mentions are known to history from other sources, so to that extent it can't be fiction, but it also describes many events, like the two creation stories in Genesis, that we now know are not true, so to that extent it's fiction. That's why in all book shops there are other categories than just fiction and non-fiction, not everything falls neatly into one or the other. In fact most things don't, the "Fiction and Literature" section in the Chapters and Coles shops I frequent occupies a small fraction of the floor space and there are dozens of other categories. Costco, however, is not primarily a book shop, it's a discount bulk goods shop and the book section of every one I've ever seen is a relatively small part of it and it's not divided up into labelled sections, it's just a bunch of tables with books all over them. There's some structure to it, the cookbooks are all in one place, current best sellers are all together, children's stuff is all together, and so on, but it's not organized like a book store or a library because that's not what it is. I'd bet the low level part time functionaries charged with putting the price labels on books had a very limited range of price stickers to choose from and didn't think much, if at all, about what they were doing, they just used what they had available. To think that this means Costco itself thinks the Bible is fiction is just dumb, this is a storm in a tea pot.
There is methodology to deer hunting?
If you actually want to get a deer, yes there is. They're very wary and not easy to get, you have to know what you're doing or you'll fail.