I directed voice acting for like one game trailer, ever. Asked around a lot, got lots of great info from a member of the team that directed voice work on Gone Home and ended up using a voice actor who was super helpful in explaining how everything works AND had his own recording studio and software which he knew how to use.
So yeah, it's very expensive to do it properly. (You can't do it improperly, of course, because then you'll get those cringeworthy moments where it's clear they had the dev team come in and pitch in for minor characters.)
Generally a recording studio has to be booked, you need a technician to run things, you need a voice director (maybe that's the producer/creative director), and of course you need the actor. But you have to call them "the talent" because that's a thing in acting. So you gotta book them at least a few weeks ahead of time, maybe months, and you'll usually have to book a full day of work. If you want to change any lines that your voice director doesn't catch in production, you gotta redo the whole process. It's pretty standard to schedule some time for redos, too, because once you have the voice work in the final form you just know someone is going to want to change something.
I'll say again, I was super lucky to work with a guy who was willing to book just an hour or two and could run all of his own recording equipment -- and that's just for a 90 second trailer!
(Okay, one more story: Was at the pub and talked with a guy who thinks he worked on some Call of Duty-like game; he had to grunt a lot and shout soldiery things. Would you believe that they get voice actors in to the studio and don't even give them the name of the game? Not even a lot of context, just like "you're a rough and tough soldier guy, now let's do some lines". Makes sense why VO can sound a bit disjointed sometimes.)
Ahem, back on topic: I would only see this being a worthwhile option for a game the scale of Starsector for doing like a 1.0 launch trailer or something, but that's up to Alex and if it's appropriate at the time!