First, you need to understand why the powers, or the world itself, should grant you wealth. That is the central question. Stories about selling your soul are just stories. Tales of rituals that make you rich are stories too. There is only one principle: what, specifically, makes someone useful to the world or to those powers?
To understand why the world should be generous to you, try a simple thought experiment:
1) Recall whom you have helped in your life, how you helped them, and when you did so selflessly, simply because your heart told you to.
2) Recall how and how often other people helped you just as selflessly. Were you grateful?
3) Think about how you have treated other people. Recall both the positive and the negative moments, and compare them.
4) Are there memories you regret? What makes them stay with you, what emotions do they evoke, and what exactly do you regret?
5) Recall how many people you have hurt, how many have hurt you, and in what situations. Compare these experiences.
6) Consider why you need a “rich life”. What would it actually change in you? How would it benefit other people and the world? What meaning would that change have, not only for you but for others? Define the purpose of this wealth as precisely as you can.
What is the point of all this? It helps you identify the resources that might make your wishes attainable.
For example, some people say you can sell your soul. No, that is a misunderstanding. In the idea of “selling the soul”, the resource being spent is the individual’s own spirituality. Usually, after demonic forces have exhausted this resource, the person loses everything. The source has run dry. Naturally, no one else will come to it. The person is left with dependence and depression.
The second possibility is spiritual work. Here you identify meaningful goals. The resource is the socially significant goal itself, supported by society because people can see that the goal is useful. That is why the thought experiment asks about significance and purpose.
So before asking for something, think about what you yourself can give. How much is your “soul” worth if you have decided to sell it? Not very much, apparently.