Academic journals are not popular magazines, and laymen basically can't understand them, so no one is interested in buying them and can't return them. Because the sales volume is not high, there is no advertising sponsorship or anything. Basically, the author is charged a page fee, which is accepted by everyone.

Moreover, core journals often charge 50-200 yuan's contribution fee, which will be paid at the same time when you contribute. The review can't be published, the paper can't pass, and it can't be returned.

Since your paper was hired only after it was hired, it should not be the review fee, but the page fee. 700 yuan spends too much as a comment, but it really doesn't cost much as a page.