$9 each, or for a pair? Daylight bulbs are running around $10 for a 2pk around here -- and those are for T8s. From everything I've seen, moving from T12 to T8 is a very smart decision in terms of energy usage. T12s are basically for home use only -- any business running more than a few lights uses T8 or even T5 these days. I always try to follow what industry does -- they've got a lot of bean-counters running the numbers for them, and they always value economy and reliability over flash (which is what the consumer market generally demands).
Not sure, but it looks like a different "Newt". Newt, care to comment?
Anyway, I like the idea of mixing the bulbs better, if for no other reason than I think it will look nicer. Two daylight bulbs might look a little blue and/or washed out. The other bulb should bring out more reds. Even better, I might use the daylight and a warm white. Otherwise, I have been having very good results so far with the Ott-Lite plant bulbs sold at Home Depot for about $9 I think. Sold as T12.