@oTwix asf ar as airy buds go your trying to light up too much plant/too much space with too little light. The LED you have is probably 135 real watts and the 3x 100w LEDs are not 100w LEDs.
For a 4x4 area with HPS you want 600w, with a really efficient LED you can do it with 400w ish. But with cheap LED you want at least as much if not more as HPS, so HPS would be a good choice on a budget comparative to those cheap LEDs.