I am all about experiments so I like Slow's idea. That said, EYE Hortilux is considered the nicer bulb. I have had great success with Sylvania's Lumalux. But...like most everything else, you get what you pay for.

If you have a public website to adviretise things and your state is somewhat pot friendly, you can often find people clearing out projects. I have seen 20 1000 watt bulbs for $400. Half brand new, half a few cycles. You...cannot beat that. If I had had $400 then, I would have been flooring it up there.