I recommend two hydra 26’s. They are a little over your budget but they are an excellent light that provide great growth and colors. Two ai primes won’t be enough for a 36x24, it will shadow and not have enough power to get down to the sand bed. Black boxes are risky. They are made with the cheapest materials possible and have fire issues. Sure they grow coral but fire isn’t good ;Hilarious. Search around! check Craigslist, offer up, Facebook marketplace, and here! There’s quite a few 26hd’s for sale out there for under $250. I know it seems like a lot of money, and it is. But lights are essentially the most important part of a reef tank. The best advice I can give you is buy once, cry once.