The Expanse is the most expensive TV show that isn't Game of Thrones--estimates are that each episode is approximately 70% of the average cost of GOT, which is currently the most expensive TV show in production. However, ratings-wise, it's not even the most popular show on SyFy, so the advertising revenue isn't that great for the channel. The low revenue, combined with the lack of alternative revenue streams (i.e., digital streaming rights, foreign distribution rights, etc.) means that the show has been a major money loser for SyFy and is one of the reasons that Comcast's cable unit has been underperforming the past 3 years. Alcon also decided to make the distribution rights even more restrictive when they came up for renewal this spring, meaning even less potential revenue for SyFy.
Rather than brand your pitchforks at SyFy for cancelling the show, you should give them credit for keeping it going for 3 seasons in the face of significant revenue losses. And you should blame Alcon for trying to blame hardball when it didn't have the leverage.
[Edit: Rome was actually the most expensive TV show; the average cost per episode was $9m over the course of its run. GOT's season 6 averaged $10m/episode and season 8 will average $15m/episode, but it's earlier seasons were relatively cheap. ]
Most production companies though will sell the right to the network to run the show at a price where the network can make money off of advertising during the first run and the production company will take the hit and make it up later.
As for Westworld: though the cast is large and costly, the actual shots themselves can be done relatively cheaply since they don't need VFX for most of them.
The world of the show and books is such a great look at a possible not long off future. A lot of sci-fi is much further ahead or not as far.
And they really are in need of something to put against a GOT-scale series based on the Tolkien universe over at Amazon's Primevideo service, which will definitely start streaming around 2019/2020.
Maybe Amazon or Netflix will pick up the franchise.
Without knowing how good season 3 is, I'd say Amazon should just pick it up.
