Can you make DIY LEDS on a budget?

I am wanting to replace my metal halides for my 120 gallon reef. The lights are expensive to run and the bulbs are expensive to replace. I have been looking into DIY LEDS since I cant afford to buy a brand for $600. Can you have good DIY LEDS for cheap, like around the $150-$200 range? Anymore then that and its gets a bit too expensive to make. Thanks.