Third! Especially if you people plan to smoke regularly, because of the health issues. My SO has a servere epilepsy (5-6 attacks per day) and is attack free for five years now, after she started smoking. If you invest ~100$ for a tent, ~100$ for venting, and ~500$ for LEDs, you will safe a lot of money after the first grow. You can also start with a smaller LED but since that is the bottleneck in most setups, every dollar you spend on an LED is a dollar woth of product you will have more. Maybe you can start with one LED and add another one ofter one or two rounds. Homegrowing is a net plus, after the first grow, if you smoke ~15g per week. Which might sound a lot now, but for three people with health issues it's not that much. Plus, this is only the first grow. After that (or maybe the second grow, if you calculate electricity, water etc).

You can even buy miniature hydroponic systems now. All you have to do then is put you plants in your tent and put a little bit of fertilizer (or molasses if you want it organic) in the water, once a week. That's the laziest you could go.