don't go budget on lights. Save up... good fixture will last 7-10 years. High quality lights only need ~30watts per square foot (you'll want a bit higher to counteract any slow dimming over that 7-10 years). Shoot for 35-40 per sq ft and you'll be rocking.
This watts per sq. ft. only work for the ~2.7umol/J and higher rated products. If they hit that mark, they have the better diodes available on market and driven at 1/2 diode power (** dioded... the 'driver' is best run at full power for best efficiency, The diodes on the other hand need to be ~1/2 spec sheet power)
Simply look for:
Samsung LM301 diodes -- these will be the bulk ~95% of diodes. they are white light, full spectrum
660nm Red diodes of some sort -- cree xp-g3 are the most efficient.
divide watts by # of diodes. if near ~.35-.40 watts per diode, you can be sure they are driven at 1/2 power. 100 diodes should be ~35-40 watts. if the fixture has 1600 diodes and ~350watts, that's .22watts per diode, so they are definitely not driven too hard. If it were 800 diodes and 350watts, that is .44watts per diode... this is probably okay, too. It is not significantly above ~.35-.40w/diode
Again, all the above regarding watts and watts per sq foot depends 100% upon the samsung lm301 diode being the bulk of the light. The greater proportion of other diodes the lower the efficacy drops... all those wattage values i gave will NOT apply. Wattage can only be used when you know the efficacy of the light. less efficient lights need more watts to provide same intensity of light.