you can get Cree xpg for almost $5. (i just bought 115 units)
get dimmable drivers!!! so you can easily adjust your overkill!
you can use different aluminum fixtures to spread your LED's no real need for heatsinks and fans. unless they are highly concentrated on one heatsink.
i did my DIY LED for 55g cost me <$90. my LFS had T5 lights for me that did not even fit into my canopy for $115, so leds are already cheaper.