Almost every professional firm presents tiers. Very few of those tiers are real, in the sense that a buyer choosing the lowest one would be well served and the firm would be content.
The usual construction has a small tier that exists to make the middle look reasonable, a middle tier everyone is steered toward, and a large tier that exists to make the middle look modest. Buyers have seen this construction. They read it as pricing theatre, and it costs more trust than the contrast wins.
What makes a rung real
A real rung is delivered completely at its own price, produces something the buyer keeps, and can be the end of the relationship without either side feeling misled. It has a stated boundary, so that what it does not include is legible before purchase rather than discovered during it.
That last condition is what makes the ladder work commercially. A buyer who can see the edge of the small engagement can judge whether their problem fits inside it. If it does, they buy it and are satisfied. If it does not, they can see that themselves and the conversation about the larger engagement is theirs rather than ours.
Why firms resist it
A genuinely complete small rung will be bought by people who would otherwise have bought the large one. That is the cost, and it is real. What it buys is a much larger number of people willing to start, and a first engagement that ends well rather than in the discovery that the thing they needed was never in scope.
It also disciplines the larger rungs. An engagement that has to be worth buying after a small one has been delivered honestly cannot be sold on the fear of what was left out.