Speaking from an artist's point of view, they should keep the fees as low as possible. Something along the lines of what Sonicbids charges (10$/month), or even less if possible. 9.99$ is price that would attractive to anyone.
I know most artists are stingy and will go with free whenever possible, but if Audigist/RTGV can offer some of true value, then a small monthly fee would be worth it.
I'm hoping the full launch will include a lot of tools and a very easy to use, turn-key system for artists to sell and promote themselves.
Right now, there are a lot of other sites that are very similar to audigist in a lot of aspects. Reverbnation, for example. I hope they can bring something new and intriguing to the table.