A tactical extension of Appeal to Self-Interest, Not Mercy: once a request is framed around what the powerful party wants rather than what you're owed, you can also choose what form the ask takes. The goal is to find something that costs the powerful person very little to grant but delivers outsized personal value to the asker — extracting large value "pennies on the dollar" relative to a direct monetary ask.
Instead of asking directly for something costly, reframe the ask as a near-costless-to-grant credit that's highly valuable to receive — e.g., "I've always wanted to be an author. Robert, I'm a huge fan — why don't you let me write the foreword?" The credit, access, or title substitutes for a costly direct ask like a cash payment.