People writing these articles are either willfully ignorant, or just plain liars.
There were supposed to be over 100 B2s and that would have brought the costs per unit down significantly.
Every procurement program's costs are predicated upon a certain number of units being made.
A lot of $$ is invested up front for R&D and needs to be recouped via the cost per unit.
Make less, they cost more. Make more, they cost less.