The last one i contacted i have very detailed information. Her is the list (only for computer games).
1. Studio (includes the record) 1 hour 120€ - 1 complete day (8 hours) 800€
2. voice-over artists
- 120€ for driving to the studio (1 artist)
- first option: for 1 take (means for example "Nothing to do here" or "Nothing to do here but i see a candle" both will cost the same cause it is 1 take) 6 €
- second option: 200€ per hour
3. Rights: No time limit to use, country borders or price of your product.
I dont asked for a lower price cause for now i only needed some numbers to calculate.
But they told me if i am ready with the whole text i need to do with voice-over, so we can make a better proce as package (i dont know how much this will be, cause for now it is to early to ask).
The good thing was they have a very big pool of speakers to chose of.
Also this all is for native english speakers the live in germany, for german speakers they told me it is similar.
And you can go to the studio and talk to the speakers if you feel like this is not the right way and they can change direct.
The two others were similar to this offer (one was lower in the price (german speakers) if they are kinda new in this business 120€ an hour).
A fourth was more for broadcast and movie productions, they want for minutes money with restrictions for example time limit 1,2,3 years.
I hope i dont forget something and this will help you