Charging for a theme made with beta development software is wrong IMO. I would download it and try it out too, but not for $7. The problem with themes is that you don't really know if they suit you until you try them. I've tried several that look good from screen shots, but when they're put into action they leave a lot to be desired.
Jason Calhoun makes some nice themes, but they don't always work very well. And he's quick to answer emails before you buy, once you buy, all email responses cease.
I'm not say xRollinx is like this, but previous experiences make me cautious.