Assuming the $8 million per regular episode number is correct, and taking the low end of your numbers, they spent $6 million on 60 minutes of content, as opposed to $8 million on around 42ish minutes. Now, the goal, remember, is to give Trek fans a reason EACH MONTH to stay subscribed until the show starts airing. I don't think releasing an audio commentary a month or bonus scenes for an ep every month gets you there. So, lets assume their experiment is wildly successful and everyone stays subscribed. That's roughly 2 million subscribers (based on the numbers we've seen spitballed around) at a minimum of $6 per month, so that is $12 million a month x 4 so that $6-9 million nets them $48 million. I would say that is pretty cost effective.