does the brand of a bulb make much difference

does it? like a $100 bulb over a $30 one what are the best and how much difference is there

there probably is a difference...enough to warrant 70$, not in my book, unless youre super rich and can throw money around( why are you growing in the first place?) i just cant see a different bulb of the same wattage giving more than a 5% gain

i think it depends on how old the bulb is, i think if it is real old then the light will def be less than if it was a brand new bulb, i am not 100% sure if the light difference is noticeable by the eye but well honestly i dont know, those are just my thoughts

In some cases it is... can't think of many... or more than one you can get a bulb for 40 bucks thats as good as the 100 dollar ones, the best bulbs for a 400W would be 430 W advanced spectrum bulbs imo.
their are duel arc bulbs (also called metal sodium bulbs) that may be worth 100 bucks, they have both a MH section and HPS, but I never saw anyone use it on this site so I cant say whether its worth it or not.
High Tech Garden Supply