These mofo's are pricing themselves out of most people's budgets!!................I don't get it.
well you can look at a illumitex "knock off" BML's spyder panel
http://www.bmlhorticulture.com/spydr-600-grow-max-spectrum/ NOT the same umol/par #'s as the illumitex, but in a 3x3 SOG environment it should work...........still would prefer passive cooled panels in a large op, no offense to area 51 and the rest of the active cooled panels. It's just less worry(also fan failure/junction temps) when your electronics are SEALED from moisture and dust when dealing with a commercial operation(employees do dumb things
).
If quality and power savings are on top of your list you may also want to look at currently the best CMH bulb
http://growershouse.com/sun-system-lec-315-light-emitting-ceramic-mh-fixture-120v the 240v option is even cheaper, covers a 3x3 @ $500 a pop, highest par/umol per watt on the indoor light tech market ATM. Very low lumen depreciation(for hid), open fixture rated, etc.
Even check out indagro Induction, I'm sure daryl would give discounts on bulk .............10yr warranty is very nice on a big investment.
good luck and be safe