cheap Metal halide floods

[Jamar]

At most home improvement stores you can pick up floods in either MH or hps in the 70-100 watt range, the hps is more costly but the MH is around $1 a watt, with the smallest option being 50 watts............my question is ....Is this sufficient lighting for a small startup in enclosed space, say 3-4 plants in closet, or just a waste of money? I have read where 4oowatts is enough for 22 plants so i was wondering how many this light would "feed".