As with most articles they got a bunch of small details wrong.
I am an owner of Bitcoiniacs, and this article is sensationalizing a minor incident. We didn't hire an ATM attendant to protect the ATM from poachers, we hired them to help people learn how to use the ATM and about Bitcoin. Also, the fee wasn't 7% at the time, it was 5%, and this "poacher" wasn't advertising lower fees, he was saying that if you wanted to buy more than $3000 (the limit of the ATM) to talk to him.
Let's put it this way: it costs so much to manage the ATM that it's a miracle we're still in business.
Ah that's journalism for you these days.
However, the cat is out of the bag now. Its actually a great idea. Go and set up shop next a bitcoin ATM machine and undercut the fees. Simple but effective, especially if the fees are high. To my mind, 5% is very high, there will always be someone prepared to do it for much less than that.