Purity of heart will not make us poor. The exaltation of poverty as a spiritual virtue is of the ego, not the spirit. A person acting from a motivation of contribution and service rises to such a level of moral authority, that worldly success is a natural result.
Give all your gifts away in service to the world. If you want to paint, don't wait for a grant. Paint a wall in your town that looks drab and uninviting. You never know who's going to see that wall. Whatever it is you want to do, give it away in service to your community.