I tried it on 1 grow and wouldn't do it again. I may have used too few, the wrong kind, etc.... but the l'il darlins didn't produce nearly as well for me as they did under mh & hps.
$100?!?!? you can get a 400hps light for $25 here: HPS Lamps
Did you use mh during veg. and then hps during flowering?
From what I've read the 400 is the most efficient hps light.
70watt hps lamps add a few of those u never know???they dont require ballasts!!