I googled some of the hardware mentioned in this guide and it seems like it would cost several thousand dollars, at least, to buy it all (I could be totally wrong, I'm not much of a hardware guy). At the current price of Ethereum, you're not going to break even for six months, which doesn't strike me as a fantastic get-rich-quick scheme. I would be delighted to be proven wrong by someone more knowledgeable, though!
Plus with difficulty increases you will soon be earning less than 1 ETH per month so break even will get further and further away. As with most cryptocurrencies that are actually worth having you are better spending the money you would spend on mining equipment actually buying ETH.
This is great if you happen to have 5 x GPU's lying around to put to use and cheap electricity to run it.