Not only that but it has only 3 scenes. Or 1 scene with 3 CG, I don't remember which one it is.
Basically, the author says they want to hire an artist. Currently, they don't have one so they have to use AI-generated CGs.
The price though... It's like you are buying a short demo worth a decent title. I wonder why not to set up an account on smth like Patreon and deliver content at steady pace to show you mean it for real? Though they probably do have a Ci-en account, I didn't check.
Anyway, it's their choice, I don't mind. I got excited by seeing the screenshots because it features one of my fetishes, but that's about it. Personally, I would gladly sub for a few bucks a month to get game updates, but paying 1980 yen flat and hoping for a miracle looks like a rip-off.