Yeah, 5,000 copies is bare minimum for most publishers to call breaking even, not even close to best-selling.
It depends on the publisher. Big American publishers, yes. But small-to-medium-sized niche publishers, or foreign markets, may have lower thresholds.
The Catholic publishing world cashes out at around 2,000 copies. (Which is still far above PA's reported average of 75.) Five thousand would be considered a good seller, with best-selling status being conferred around 10,000 copies.
The same is true for Canadian books (secular or religious), where 5,000 is threshold for best-selling status if I am not mistaken.
But even by these lower thresholds, only one of PA's tens of thousands of books meets this bestselling standard.
P.S. No, I haven't heard of Joe Gadreau. So I'm not likely to buy his book since it isn't on the bookshelf of our local bookstores, nor has it been reviewed by any of my favorite book reviewers. Nor, as a book reviewer myself, have I received a review copy. And given the number of books by established writers on my reading list, I'm not looking for more unless an author captures my attention.