It's easy to get a lot of money

According to this movie, you can come from a world where money doesn't exist, shopping doesn't exist, any kind of 'monetary transaction' is just long-gone history, there's only war and survival and stuff like that, and just instantly have lots of money.

Because someone doesn't want to know how you got it, the movie never explains how this can be done, but apparently it's easy. If someone who can't possibly even understand the value, or even the concept of 'money', can just easily somehow 'own' a big bunch of bills, surely anyone can?

Shame on homeless people for not becoming instantly rich, this movie shows it's easy and hassle-free, even the cops won't be interested in that.

It's interesting to note Kyle got this money AFTER they escaped the police station, so he couldn't have gotten it at any point earlier (unless they somehow, amidst trying to flee the police station and a killer robot happened to be able to not only find the place they store prisoners' possessions (probably somewhere that's locked up), but also casually gather all those possessions, and they were careful to ONLY take their on possessions, not anyone else's - EXCEPT FOR THE MONEY).

What kind of sense does any of this make? At what point did Kyle have the TIME to do this business that earns him so much money? Did he steal it (I assume he did), but from whom, and how did he manage to do it in an 'invisible and undetectable way'?

How do you acquire a big pile of cash without any hassle, or raising any suspicion, and how can you do it without someone you're constantly with, not even noticing?

HOW DID HE GET THAT MONEY?

I mean, according to what we're shown, it should've been pretty much impossible - I am not even going to ask about the gun..