Paying $0.00 is technically
not paying, so hush.
And if you're a horrible and slapworthy cheapskate and enter something below a dollar, a funny little picture comes up,
asking for at least 1 $ (think about PayPal fees etc.). But that's all. Technically, you could still pay $0.01 (and should consequently be banned from playing good games forever). In short: You heard wrong.