Everything is fake, he's a clone who works for the company and if he figures it out, they kill him and uncork a new one. Any time he dies on the job, they uncork a new one. And every three years...they replace him anyway. I hope I'm wrong and there's another twist.

Yes, it was a station setup to use clones instead of sending new people up to replace the worker. Clone A does get into a crash, and the computer awakes a new one. This happens 2 weeks before Sam can go "Home", but Sam aka clone A did not die, and the new Sam clone B finds him alive (a bit more to how this happens btw). Sam B returns him to the base, but the computer does not kill him or the other.

It's there to protect (make clones happy) no matter what...as you learn later on in the movie. I would think the computer would kill both clones to reset everything...but it does not happen.

Oh, the clones only live 3 years anyways, and Sam A was dying during the movie. And he the video logs of the other clones come to an end of their contract thanks to the help of the computer. This was the first time the program went wrong.

The first thing I would think is... how is setting all this up cheaper than just sending a real guy there?

I don't think its really about saving money but rather using clones instead of real humans and keep them in space for years at a time alone.

Then again, the salary demands for a job like this would costs millions because no one would go in space and leave everything behind for cheap. Yeah, I guess it comes down to saving money because the clones work for free! They were planning on long term investments, compared to short etc

You see a huge underground area with thousands of clones (well a lot of them) So, they were going to be using them for 100's of years and stuff