You can totally do it. Here is what I am doing right now:
Veg Box:
-24"x24"x12"
-100w MH bulb, remote ballast
-PC fans for cooling (10 for $10 on newegg.com)
Flower Box:
-30"x18"x18" (its a mini fridge)
-70w HPS, remote ballast
What I'm doing is vegging in my veg box, taking clones and flowering them in my flower box. This way I can always be flowering and vegging plants. I'm doing this in my closet, in my room at my parents house (stayed with the rents while getting my BA). I've flowered a plant all the way in there once and no one really seemed to notice. It smelled pretty strong, but if you set it up so that the lights in your flower box don't turn on until 9PM your it should be ok. My logic is that around 9 is when I usually smoke, and it smells like weed in my room because I'm rolling or vaping. The smell from one or two small plants isn't much worse than a bag of dank left sitting out. IDK, I have mmj though, so my family is a little more lenient, and they aren't nosy either.
I'd say I spent a total of $150 on the whole setup. Look for an old Mercury vapor ballast and put an MH bulb in there, as long as the wattage is the same it should work, you'll save some money that way. I'm using ballasts from home security lighting for my setup. If you want to check it out, go here:
https://www.rollitup.org/cfl-growing/307706-mini-fridge-grow-2-a.html.