If you're not opposed to used equipment, keep an eye on Craigslist. I got my current setup for $400, which I consider a steal:
1 4X4 grow tent (Secret Jardin, for flowering)
1 4x2 grow tent (generic, for veg/mothers)
2 air cooled hoods with 6" ducting
1 400 watt switchable ballast
1 2 foot 4 tube T5 (Pioneer II) for sprout/veg
1 4 inch can fan (for air scrubber)
1 6 inch can fan (for cooling lamps)
Add to that ducting, nutes, soil and carbon filter, I spent about $600 altogether. I have a cabinet I use for sprouting or clones, depending, but could easily sneak them into the smaller tent.
I also had another old 400 watt HPS I add to the flowering tent for anything over 4 plants, so you're talking around $600-$700 or so for used equipment and an ideal setup, I'm sure if you were vigilant you could score something similar for $500. I grow for one other person plus myself and could easily accommodate another patient. If you have basement or closet space, forget about the tents and save yourself that much more. If you wanna go hydro add in another $200 give or take to build your own setup.
Anyway, there are a lot of failed first timers getting rid of their barely used stuff on Craigslist (at least around here), if you're patient and check regularly (the good deals seem to go pretty quick after being posted) you can score.