It depends on which bestseller list you're talking about, and it depends on how sales went across the board that week. "Bestseller" means this book sold more than the books below it this week, so how many you need to make the list, or top the list, changes each week. Some lists require very few sales, others require a big bunch of sales. It also depends on hardcover or soft, adult or YA or children, fiction or nonfiction, etc.
It does seem something is wrong with the numbers on Falke by Federico Vegas. 10,000 copies will make you a bestseller in many countries, and on many lists, though this is tiny compared to the NYT list, but a book that's gone through three editions should have sold more than 10,000 copies, though this may be American market thinking.
Anyway, being a bestseller in Venezuela is not the same thing as as being a bestseller in Australia, which is not the same thing as being a bestseller in England, which is not the same thing as being a bestseller in the U.S., which is not the same thing as being a bestseller world wide.