^^^ Naw just don't be late on your bill and always pay it! You can run about 3 600W HPS for around $100 a month or less easy and that's including water and air pumps/fans. =)
You can get everything you need online if you don't have a hydro shop nearby. I've had good experiences with HTG supply and their prices are very reasonable. I'm also going to give Discount Hydro a shot here shortly. Then there's always Amazon and E-bay, just be careful of the super cheap junk on E-bay.
Here's what I would do with $7500 and that amount of space and still have more than half that $ left:
-3 or more 600W digital HPS light kits + ducting/hoses etc. to hook up all the cooling/carbon filter. (At least 1 for veg and at least 2 for flowering, some people like MH for veg better, I think it's a personal choice. I'm all about HPS all the way.)
-1 4-5 foot grow tent for the VEG area. (Unless you plan on building out a separate veg area in the room of course.)
-1 really nice carbon filter/fan setup.
-3 ebb and flow flood table setups (Maybe like a 2'x4' for the veg tent and then 2 of those or bigger for the flower area.) 1 for the veg tent 2 for flowering, 2 reservoirs again 1 for veg 1 for flowering using rockwool or clay pellets and baskets. (Or I'd do a CAP ebb and flow controller unit and buckets for the flowering part.)
-1 CO2 tank setup.
-All your testing tools, PH, PPM, etc.
-Good nutes: Humbolt Nutes, General Hydroponic, Dyna-gro, Canna, all are good nute lines, just don't feed into the hype of all the crazy additives too much. (I like to keep it simple so I'd probably do Dyna-gro's Grow + Bloom + Pro-tek with maybe some beneficial bacteria like Great White or something.)
-Good seeds/clones! I can't stress this enough don't waste your time on inferior genetics, it's just not worth it.
-Everything else that comes up, and there will be lots of it!
Now with that setup what I'd do is try and run about 24-48ish plants at a time and then stagger them so that I had a harvest once a month or so. So start like 12-24 depending on if they are fem seeds or not then after a month or so move them to the flowering area after culling males/taking clones if necessary and then rinse and repeat every 30 days. You could even double up the stagger so you have a harvest every 2 weeks. That can be tedious though, harvesting once a month I think is a cool setup. =)