economical except lighting

[cubenis]

Dear Ron, Great site! But I've got a problem. I am trying to do a hydroponic garden on a very limited budget. Everything about hydroponics seems to be economical except lighting. The price of lighting is way, way, way out of my budget. Do you have any suggestions on cheap lighting? What about fluorescent lights? I have lots of 4 foot fixtures for free, I would only have to buy bulbs. What about the outside lights that come on at dark (street lights). I think they are HID. Any help would be great.