Interesting hypothetical.
Lets take a recent blockbuster. The first Twilight movie made $392,616,625 in the box office, $194,881,773 in DVD sales for a total of $587,498,398 (almost 600M - pretty good rake)
In your $5 they'd have to sell 117,499,679 of those $5 streams in order to make that equivalent revenue (so roughly one in every 60 people in the world need to buy a stream).
For more fun take the last Twilight Movie (Eclipse) which was a bigger draw ($826,423,724 total revenue). Then you'd have to sell 165M streams to get to those numbers.
Considering the $5 stream scenario could be shared across a family - I honestly am not sure your assumption that a studio could make more money is correct. The real X-Factor here is the cut the various distribution chains take.
I'm not sure your price point is right, but would you perhaps pay $20 for the same stream?
EDIT: Also I don't think the 4-weeks after theatrical release is going to work I don't think theaters are going to show your movie if you're going to kneecap them 4 weeks out.
[0] http://en.wikipedia.org/wiki/The_Twilight_Saga_(film_series)...