Sometimes I think that buying so many of them doesn't really affect if you get a secret ayupan or not. Two of my friends both got one, one of them only purchased 10 of the AT09 ayupans, and the other friend purchased 11. It's totally random. Which is why I'll probably stick to buying only 10 or so of them, depending on my money situation that week. If I bought 50 and didn't get a secret Ayupan, then I'd probably be rather annoyed.
