Why is Conan's zebra limit so expensive?

Why is Conan's zebra limit so expensive? I didn't mean to sell at a high price, but the restriction itself was not mass production. If there is a certain scarcity, the price will be fired. For example, Bai Le used to have more Bote bottles than 4 yuan, but now the price has doubled. According to normal thinking, Conan's traffic should match his black pen to get sales blessing.