From what I have experienced in any casino including casinopunk which I played some time ago. betting at $0.2 either when getting a free spin bonus or buying it never gets a profit above $10. Either I'm unlucky or the provider I play is not that good. Usually the PragmaticPlay provider is my favorite but in the future maybe I need to move around a bit to try whether $0.2 from buy spin exceeds $ 10 or not.
Not all slot providers or games are created equal. And your betting strategy can make a big difference in how your returns pan out. But if you ask me, I think you maybe mistook being unlucky for a bad provider, which is unlikely unless you were playing on some unknown platform. The games are heavily regulated so there is not much influence that casinos can have on games.