I’ve tried it a couple times, it’s neat, lots of features, but that makes it a bit confusing. I’ve also had trouble finding a stable English speaking general purpose server that’s reliable, all the one’s I used were down more than they were up. You might want to look at Calkey or whatever they’re calling it now, that’s an active fork.
Celebrities don’t always cost much, you have to remember that those high rates they get paid are optional, there’s a base pay for actors, and they can take that rather than their typical high pay if’n they want. Throw in that in a lot of ways voice acting is easier (no costumes, make up, no standing around for a scene to be set up, etc), and it’s effectively a quick and easy buck for actors.