Now this isn't just speculation, my granddad helped me with this and he used the same technique on the way back from America at the San Francisco international airport on a family holiday, he just couldn't handle economy on such a long flight so he bought a suit for Â£30/$70
This may have worked, back when his granddad could buy a suit for $70 and look like a businessman, but it's not likely to work now - at least in the U.S.
Even 10-years ago, I'd frequently get upgraded to business class when a plane was overbooked, just because I looked professional, but these days upgrades are given based on your membership in the airline frequent flyer club, the amount you fly on that airline or the credit card you used to purchase your ticket. Most of the US carriers have taken the human element out of the decision and turned it into an automated process.
Of course, the author may be foreign and I don't know how the upgrade process is handled in other parts of the world.