I am the only one who bears the financial burden at home. My wife wants a mobile phone, and I want her to pay by installment (interest-free). Is it too much?

Staging is not much, but your relationship between husband and wife has reached a dangerous level, which is a bit too much. You should pay attention. She keeps complaining that you can't do this or that, which is a kind of dissatisfaction and disgust for you. If this continues, it will not only hurt feelings, but also make it difficult to live together in serious cases. You should try to change the status quo and get rid of this situation as soon as possible. Husband and wife can only understand, respect and support each other.