Originally Posted by G.W.

no need for a dimmable ballast
no need for a digital ballast
no need for a ballast that will run MH

600w hps conventional ballast about $120
2x Mogul base about $10
3x 600w hps bulbs about $35
30A DPDT relay with 120v coil about $25
Some 14ga romex dirt cheap or use 12ga ext cords
Generic 2 prong timer $5
Homemade batwing reflectors FREE from paint cans or wire frame and aluminum foil
The whole deal will be less than $200 and the relay allows 2 bulbs in seperate locations to run 12/12 from a single ballast.

Hey at least you weren't asking about LEDs......