The ladder is just the order of asks. A small yes, then the course, then the thing your best students already want. Each step should be sellable to the person created by the previous step. That is the whole strategy behind “sell more to the audience you already have.”
Bumps, one-click upsells, and evergreen deadlines are mechanisms on the ladder. They are not the ladder. If the next offer is not something this buyer can recognize as theirs, no checkout trick will make the sequence feel fair.