How much does the #1 spot cost?
The honest answer is that nobody sets it. The price of the top position on this board is whatever the current leader paid, plus one dollar. That is the entire pricing model, and it means the number moves on its own.
Why the price climbs
Every new bid has to beat the last one, so the floor only ever goes up. Early on that makes the top spot absurdly cheap, the first listing on an empty board pays a dollar. As soon as the board has an audience, the same position starts costing what that audience is worth to somebody else.
This is the opposite of how ad platforms price. There, you bid against strangers in an auction you cannot see, and the clearing price is hidden from you. Here the price is printed on the page. You know exactly what the person above you paid, because it is written next to their name.
What you are actually buying
Not impressions, not a time slot, not targeting. One position on one list, held until somebody pays more. It might last a month. It might last four hours. The risk of being outbid quickly is real and it is the reason the price stays honest, nobody overpays for a position they can lose by lunchtime unless the traffic justifies it.
How to work out what it is worth to you
Look at the click counts. They come from our own redirect, so they are visits, not estimates. Divide the price of the top spot by the clicks the listing above you has collected and you get a rough cost per visit you can compare against whatever you are paying elsewhere. If that number looks bad, do not bid. The board only works if the people on it are getting something out of it.