The main advertising in Solata was done by forums dedicated to BG3. It was so much that I wonder if the developers themselves decided to get free advertising.

Certain elements are hard to justify with a low budget.
Without a large budget, you save on certain elements in order to be able to refine them, otherwise none is well made.
If you cannot afford the movie dialogs, you display a window with the text.
If you can't afford good character models then you don't do character close-ups.
If you cannot afford full sound, you either give it up in whole or in part.
I could list goes on. The most important thing is to measure your plans against your budget. Otherwise the game will come out either broken (see Cyberpunk) or bland.