Child Genesis Themes by ZigzagPress
ZigZagPress build themes exclusively on the rock-solid, secure and search-optimized Genesis framework. They offer a variety of premium Genesis themes, and you can access all them from as low a $89.00, which is renewable yearly with their theme club.
You will get one year access to all their themes, support, updates, unlimited domain usage and the option of a 30% renewal discount which isn't automatically renewable. You can upgrade or cancel your account at any time, and you are free to use any themes you have downloaded during your active membership. Apart from StudioPress, this is a particularly good offer from what I've seen on other websites. ZigZagPress Genesis themes can only be used with the Genesis Framework which needs to be bought from StudioPress.