Why do I need writer:
For good lewd content, and process of finding good writer - little simpler, than artist, but just little. What takes most time here - is control for writing. Reading it while it's in progress few times per day/week, work on corrections, cut what I don't like, request needed additions, and etc. Last we cut near 30 pages of text, with scene, because, I didn't liked that as whole scene.
And You can try to find pricing of good adult writers if You are curious.
All other dialogues, main story, small dialogues, descriptions of everything - I'm writing by myself. Same about location design, search and assemble assets, since often You want this tree from this set, and that chair from other set.
Battle system, and deviant reactions don't use custom coding. I used few plugins, that can be found for free(of course author are credited on Patreon page), and and spend some time to make, test, and polish those systems.