The article is all about the cost of the hardware, neglecting the more significant cost: electricity.

Once you're above baseline power of 11 kWh/day (as any geek is), Southern California utilities get about $0.13/kwh marginal, with taxes, distribution, etc.
The 24-core beast built in the article probably draws some serious current.  Hard to guess how much, but I'd guess about 500W?  Anyone know?

This will add 360kW/h a month to your electric bill, which will easily drive you into the next pricing tier, or maybe two tiers higher.  Now your marginal power can be $0.18 kW/hr.
Yikes.
That bitcoin miner would be about $2/day to run, or $788 a year, which means you've never matched the hardware cost of the system in two or three years.

If you have to actively cool the room with the computer, at least during daytime, double it again.