Ok so according to @dexterlife1985 volume 77 of Gintama will be released on July 4, will not be sold for 440 yen ($4) (like every volume in a series Jump), but 700 yen ($6.36). So it'll probably be 300-ish pages or so.

— Kewl0210 (@kewl0210.bsky.social) (@Kewl0210) May 18, 2019