Are there any third party brand flashes that act as a master flash for a Nikon d5000?

I own a Nikon d5000, which has no on camera wireless flash command, and a Nikon sb 50dx flash. Is there a third party brand flash ie bower, sunpack, etc… Which will function as a master flash for my sb 50dx? I'm not looking to drop $350 on a sb700.

The D5000 has a built-in flash that can be used to trigger external strobes via a sensor. The only thing you need to do is be sure to put the camera on manual, and then adjust the setting so that external lights determine the exposure rather than the on-camera flash.