One year meeting at least once a week for an hour amounts 520,000, we know there were instances they hangout for longer, or when he had to pay food and transport, or when in the summer he paid an extra for her being in another city, so 520,000 is a low estimation not considering some of the manga events. Not only that, we know he had 1,000,000 yen in his bank account and he probably started working because he spent at least most of it on her, so I wouldn't be surprised if he spent over 1,000,000 yens on Chizuru, he gave her enough money to fund half of her film.