I'm in the UK so I don't know if this advice will apply to the US, but after paying around £80 for a 400w hps with digital ballast, I was more than a little bitter to hear from a friend that they had picked up a similar 1000w system at a police auction for less than £10 (paying cash and not having to provide ANY id or details at all). As there is nothing inherently illegal about a bulb/reflector/ballast itself, but they are frequently seized as part of cannabis busts, apparently such items are frequently auctioned off at ridiculously cheap prices. Might be worth looking into in your area if you are on a tight budget.