HTG Supply has good prices on 400 watt systems. A 400 watt HPS or Metal Halide ballast, cordset ,reflector and a HPS or M/H bulb for 119.00. Or you can get the conversion ballast combo for 169.00. I bought of their 400watt conversion setups last year and have had no issues with their performance. Plus their customer service is top notch in my book.