Do you do much DIY stuff?
There are other ways to light a corner tank.
I'm like you... can't afford the fancy stuff... so, I made my own. Built my canopy from scrap I had in the barn, then retro fitted an old landscape light into it. 250 watt MH. Found a person local (somewhat) that was changing bulbs and picked up a pair of bulbs, 4 months old, for $40.
Hope this helps... Just trying to save you some money.