So you’re thinking of hiring someone, like me, to do voice over? One thing I believe is highly recommended before you just outright buy is #1 listen to the previous work on the gig.
Do you like the quality? Is the tone and flow of the voice what you need?
And #2 if you like the voice but want to know how it sounds a certain way, you can talk to the seller. The seller can then tell you if they can do that voice or not and they may even get you a short demo of your script just to make sure it fits!
I like to think of it as shopping for anything at a local store. You want to see it and feel it out before you buy. This is definetly true for voice over as well