Saw this online, thought it would help your decision:

"An Honest Look At The Phototron"
By Dr. Clone
Originally posted at CannabisCulture.com
Publishers Of Cannabis Culture Magazine
PO Box 15, 199 West Hastings
Vancouver BC
Canada V6B 1H4

"Amazing Phototron". I and a few fellow growers have a big problem with the claim of 6 to 8 ounces of bud every 45 days with a puny 250 W (18,000 lumens) of low intensity fluorescent light. You will need at least one 400 W halide to get 6 to 8 ounces of bud every 60 to 70 days.

Fluorescent light gives you 80,000 lumens for each 1,000 watts at 30% efficiency. Metal halide light gives you 110,000 lumens for each 1,000 watts at over 40% efficiency, and the best phototron has 18,000 lumens. About 250 puny watts.

This would explain why any who want real buds use halide lights. Buds are bigger and three times as dense and resin glans will be at least 50% larger. Fluorescent light is not cost efficient for flowering pot.