power consumption would need to be considered too. 8 54w t5s would be about 4 amps, 2 250w MH are about 6amps. so lets say 10 hours a day for 30 days. 8 t5s would cost you about $15. MH would be about $21 (at 11cents per KWh)
considering t5s are about $25 each, that's $200 for 8 bulbs, in comparison, $200 will buy a very nice pair of MH lamps.
so in the end, it'll cost about $60 a year more for MH.
hmm...makes me want to reconsider t5s
