Yeah Right

Take a look at home depot or lowes in the security lighting for those lower watt deals in Hps... sry to evesdrop but checkin in w/ a freind of mine and kinda followed your post as it interested me.. I just did a 38 gram harvest off 1 in soil under tubes and a 150 watt Hps

If your 3x3 space is ventilated enough - or if you have a way to keep things cool (even just cracking the door open). Go for the 250w HID. You'll notice a big difference in days. it covers a 4x4 foot area (16sf) so it will be a lot of light for the area you're covering. more than enough. You can still use your fluorescents for cloning and vegging. Keep the light between 8 and 12" from the top of your plants and let me know if you get a 250!