All the previous Season 16 episodes ranged between pretty good to outstanding, this is one of the few seasons of the original 'Law and Order' where there is no episode that is less than decent. The premise does sound quite ordinary on paper, but have said a number of times about 'Law and Order' often in its prime years doing incredibly well at making something special or at least more complex out of premises that sound less so. In the right hands, "Cost of Capital" had potential to be one of those episodes.
Thank goodness it turned out to be exactly that. To me, the second half of Season 16 was even more consistent than the very good first and "Cost of Capital" for me was one of the best. The story does sound familiar (there are many episodes of the 'Law and Order' franchise that have dysfunctional families with dark secrets), but the execution didn't feel so much, thanks to the strong supporting characters and the truly shocking revelations in particular. Making for one of the season's most disturbing outings.
Maybe the list of suspects was narrowed down a little too early.
Otherwise, "Cost of Capital" is great. It's an intelligently and tautly written script throughout, especially in the latter stages, and sympathetically directed. The production values are slick and have a subtle grit, with an intimacy to the photography without being too claustrophobic. The music isn't used too much and doesn't get too melodramatic.
Furthermore, the acting all round is never less than very good. Can't fault the regulars, Sam Waterston faring best, but the supporting cast are even better in more colourful roles. Lisa Zane and Keir Dullea really unsettle. The supporting characters are interesting and their dynamic is hard to forget.
While the story starts off a little too on the simple side, it actually quite quickly became quite twisty without being too full of turns and they don't feel confusing. The episode contains the mos dysfunctional family of the show in a long time and the secrets contained here are some of the show's most twisted, they actually disturbed me.
Summing up, great. 9/10.