I'm going to go ahead and say yes, there is such a thing.

In the brief period of my life where I actually completed a game, I went looking for voice actors on youtube. I was pleased to find an overwhelming number of people who were pretty much unknown (they have 10-100 subscribers or something) and yet their voices sounded amazing. I found a girl to voice my female character for a total price of free, and it sounded really good.

I think you'd need to start networking on twitter. I have a whole ton of youtubers in my twitter followers, most of them have less than 100 followers and if you see someone who's voice fits, well "if you don't ask, you don't get"...

Hope this helps!

21 hours ago, Armantium said:

That's just what I am looking for, but your description of finding "someone on youtube" is super vague and unhelpful.

Is there an agregate site with all the audio samples?

Also, there is a huge difference between voice-acting for narration and voice-acting for a character.

In my experience, you get what you pay for, as long as you don't overpay. I would start by talking to your state film commission, even if this is for a video game. Just ask them for a list of voice actors, or a casting agency that can refer you. If you contact a casting agency, I think the best thing to do is call and ask who they have within your budget. 

If you're wanting people to do this completely for free, I don't know what to say. I can't help you there.

20 hours ago, Armantium said:

How much would one charge per 5 minutes of work?

5 minutes of what? By the time you open a DAW, move a mic into place, load a template, and dial in your interface, record the passes, tweak your processing chain, bounce the file, convert it to whatever the final deliverables are, then upload it to email or dropbox, you can blurt 5 words into a mic and easily be at 5 minutes of billable time.

If you are looking for 5 minutes of recorded, edited, polished, finished, production ready audio, at the very least, you're going to end up paying $200-$300 for an experienced reliable professional, who's also going to review the lines, communicate with you about what you're after, and edit it themselves. I do know voice actors that would be happy with $250 for a half days work, but this is not simple stuff if you want it done efficiently and done right.

I've heard it said that a pro actor will usually have a higher bid amount but in the end save you time/money because they can more consistently hit the right mark. An amateur may have a lower price but is much more of a risk, may require more redirection and may end up costing you more time/money in the long run.