The cost of light fixtures in this hobby is out of hand. I work in the lighting industry and let me tell you they do not cost this much.
Sure the aquarium market is smaller and this can raise prices some. The cost of some of the colored leds like UV can cost more but come on..
Those little light diffusers they have now for the radions cost almost nothing.
I was at light fair this year and they have so many ways to diffuse led lights with different diffusers it is not funny. Lighting indirectly is another great way. The hobby is so far behind in this respect.