How are "modern" science shows economically produced?

(I feel the question should be GQ, but it’s a CS kind of topic. Mods, please do as you will.)

By “science shows”, I mean the shows you see on the Science Network or the Discovery Channel - like “Through the Wormhole with Morgan Freeman”, “Into the Universe with Steven Hawking”, “Inside Planet Earth”, etc.

They use location shoots for really small segments*. The CGI is mind-blowing, given that we’re looking at, supposedly, low-budget productions. They look expensive, but they really can’t be as the economics likely don’t support spending 7-figures on each episode.

Then there’s that show with that young guy who travels all over the world filming animals. For a couple of minutes, he’s in the desert. Then the ocean. Then Antarctica. Etc, etc, etc. This can’t be cheap.

So, how is it done? Are the costs amortized? Subsidized? Am I merely incorrect in how much it costs to film these shows, and what I think looks like a million dollars is really 1/4 that amount? Any information as to how it’s done is appreciated.

*One I saw the other night had Michio Kaku in a Pennsylvania steel mill to merely make the point that the early Earth was hot. Total show time in this location - less than a minute. Then there were other location shoots, and CGI showing stuff exploding, and damn… it just looks expensive as all hell.

I suspect that these days, even really nice-looking CGI is pretty cheap to do.

Some of those shows are expensive. The Planet Earth series (11 episodes) had a budget of 16 million British pounds ($26 million at today’s exchange rate, probably more at the time), spread between NHK, BBC and Discovery Channel.

Also some of the CGI may be “free”, made by scientists or the public outreach arm of the science organization. NASA spends a lot of money on public outreach, and that includes CGI work (like the Curiosity landing sequence we all saw).