Devs who have Patreon and Steam releases all do it a little differently. Love of Magic, and Love & Sex Second Base, basically update Steam and Patreon at the same time with their beta branch. Being a DIK, updates every 4 episodes on Steam, and calls it a season. City of Broken Dreamers updates Steam every main chapter. But really Patrons are supporting the Dev and not just the game, so usually pay for the game many times over as that is how Patreon is set up. Steam and Patreon are just different animals, so you can't really compare prices between them.