You beseech an otherworldly entity for aid.
The creature does not have to technically obey you, and might ask for a favor in return for service.
As a rule of thumb, a task that can be measured in minutes requires a payment worth 100 gp per minute. A task measured in hours requires 1,000 gp per hour. And a task measured in days (up to 10 days) requires 10,000 gp per day.
Casting this spell carries immense risk. While you may invite a specific servant of the power you invoke, you can't control or compel it. The desired bargain forms a mystical contract, but as the air shimmers and tension grows, uncertainty pervades. The summoning dance remains a delicate negotiation, where promises and uncertainties intertwine in the ethereal space before you.