That's straight from the file sizes of the PC version, most recent patch.
Money: No.
Time: All the voice files are all 64 kbps cbr MP3 files, in other words: There's over 60 hours of voice acting shipped with the game. Even with a ten-to-one ration of recording time to result time (which would be extremly good) and four hours of voice recording per day (which not everyone can even manage), that's something like seven to eight man-months of recording.
I think I've found our problem, Why is oblivion only around 4.6gb, when red dead redemption managed to be 6.7gb on a single disc? This means Beth managed to not use 2.1gb,
Let's look at the break down again:
Total amount of data alone in Oblivion.
AI, physics, game engine, graphics engine, and several different other parts all combined: 7.19 MB
Voice: 1709.35 MB
Textures, models, music and sound effects: 2136.05 MB
All the other stuff (quests, NPCs, game data): 235.92 MB
Now we have 2.1gb we can spend on this. Now let's say we want 3 times the amount of quests in Oblivion, that 707.76Mb,
boom, now we have 1.393gb left. Now
if we want those extra quest to have voice acting, we could put the rest in voice acting. I'm guess you're not gonna agree with that, so obviously if we make the quests require a minimum of voice acting, either by getting them through letters/files/posters, or by having them not all involve a [censored] load of conversation, we could put 500Mb in voice acting, because we still need some servant to say "We would like to have you look into this issue" *hands PC a file*. 893Mb left, I've already gotten what I wanted, I would probably put the rest in Textures, models, music and sound effects, because I want the weapons and skills back from morrowind, well actually also some from daggerfall. Now we have a fully voiced game with a lot of logical text based mission.