I get offering discounts for large-scale use, because otherwise the rate card might go beyond what it would cost to recreate your product inhouse. But no publis

I get offering discounts for large-scale use, because otherwise the rate card might go beyond what it would cost to recreate your product inhouse. But no published pricing even for prototyping? "I am altering the deal, pray I don't alter it any further" is what runs through my head. What happens when we're seriously dependent on it?