Basically, yes. Just don't over water it. When you stick your finger in 2" or so, is it still moist? When it is getting dry-ish, water it just a bit until a little bit runs out the bottom.

All you need to grow a plant is an area that is 2'x2x'3', a couple CFLs, a 3 gallon pot, and some nutrients to give it.

I don't know what soil you started in, but I hope it is not miracle grow! If you start in a soil that has alot of fertilizer in it, the plants will get burned by how much food is in it.

If you want to grow this thing out, I would suggest that you first scope out an area, post a picture of it, and I'll help you from there. How big is your bathroom? Do you have an area big enough that you can devote to it?

You could continue the grow for around:

$6 for a 24 hour timer
$5 for a bag of soiless potting mix
$3 for a 3 gallon container
$20 for the nutrients (Anyone know what cheap nutes he can use? Tomato ferts?)
$15 for light bulbs
Water- If you have a purification system, then that is good, but if not, you might have to go buy filtered water (buy a 5 gallon jug then refill it for $1.25 or so). They only need about a litre of water every 3-4 days when they are big.

So do you want to do it? Grow it small for fun then toss it? Plant it in your backyard?