Definitely. So far it seems a sizable investment in hardware is needed. I recommend checking your local craigslist for a budget gaming computer. It seems that'll be what I turn this machine into.

Word of warning: I'm not sure the ROI on this stuff.

Yes, it is providing a small passive income. I've mined almost 0.02 ETH now, after just over two weeks. That comes out to about $9 at current market price. If we return to the all time high, it'll be worth almost four times that, so that's where the profitability happens. its somewhat of a double gamble. you're investing in a lot of hardware that's expensive even when you get a good deal on it, and you're hoping like hell that the market rebounds.

$20/month isn't bad. It's not insignificant to me, but it will take over a year for each card to pay itself off. And that's not considering the cost of electricity. A market rebound would make the whole operation super exciting.