These avn's are made with the engine provided by HoneySelect if I'm not mistaken. No mater how hard you work on them and how amazing they can become, they are basically just like some mods. You can't claim ownership of that, let alone sell them. So there will be no listing on steam. The safe thing to do is donate money to the developer on patreon. Not for the game, but for him, cause he might be a great person :)). I don't know if you noticed, but there is a reason for the "name your price thing" on itch. You don't buy, you donate. The moment someone will try to sell this types of avn's, there could be lawsuits. There are some that can be bought, but not this type.
If you want to make money on steam, you have to make your own products, using licensed tools, like DAZ3d or something else.