http://fishneedit.com/3ft4bulbs-with-l34.html ?Yah, it was more to show the difference in price, I don't think I found a single 36" t5ho for under $300. Why would the output of the bulbs differ fixture to fixture?
Output of the bulbs differs from fixture to fixture based on ballasts. A good ballasts delivers the full potential to the bulbs and the maximum output. Bad ballasts deliver less then the full potential to the bulbs and less output.
It can also depend on the quality of the bulbs. Usually stock bulbs are all bad to varying degrees. But Aquatraders/Odyssea tends to have a triple whammy. Bad ballasts, improperly wired moonlights (which is generally why their moonlight LED's blow within months, if not days) and horrible bulbs. Fishneedit tends to be okay on ballasts and a little below average on the bulbs (really, none of the fixtures come with great bulbs).