AgentBirdnest: Even plenty of free games and mods have voice acting. I recall one mod for Deus Ex, where the creator simply asked his friends to do some voice acting, and it turned out great. So that can't be entirely a cost issue... Then again, I don't know much about this stuff :-p
I understand voice actors cost money, but it's not like you are getting hollywood celebs to voice act the games. I think many don't as they don't have to. People give indies a free ride for a lot of things, things that would get AAA games slated. And yes the AAA games cost more, but that is not always the case. We have had many indie games that are nearly as expensive, and indie games in general seem to be going up in price, meanwhile the production value is not. If you are going to charge so much, then at least provide a decent standard. If games made over 20 years ago had features, then surly modern games should as well. As you said, even free games have things that others do not. I am not having a go at indie developers, but I just feel they have used the indie card too much to excuse a lot of bad practices, getting a free ride because they are "indie". For example, an adventure game in 2015 should have voice actors if they are charging a higher price for it, especially when you can get dozens of other adventure games that charge less, have full voice acting, and are often so much better, despite their age.