For a bit of backstory, I had already decided to leave Memphis for reasons that had nothing to do with job or pay, and was literally in the market to go anywhere. Shortly after casting my resume to far broader nets than I ever had (I had interest from companies in London, Australia, Boulder, CO, Bay Area, etc.) we took a vacation to visit some friends in the Annapolis area and I fell in love with the place.
With that, I decided to refocus my job search and someone I'd known years prior hired me on for a security-clearance required position in the federal government at a job I'd never done (but which he thought I was qualified for). Because of the customer, my contacts, and the cost of livings increases, I was paid a salary well above the "2012 average base salary" for a Google engineer per the linked article. Before that, I had made something like $60k.
Except for some very specialized positions (SAP, EMC, etc.) in Memphis, I don't know of any engineers making much above $100,000 (though indeed $100,000 in Memphis is a very respectable salary.)
Since leaving, I've had a number of Memphis-based employers trying to buy me back into the area, but the discussion generally dies when we get into money as, at least from my anecdotal experience, wages just aren't that high around there, and the only large paying employers are those who have successfully commoditized the market (FedEx, International Paper, etc.) and aren't hiring 'rockstars'.
In summation, while I'm sure there are people making what I make or above in my field in Memphis, it is by no means as common as a six figure salary in the valley, or bay area, or in places where there are large IT-based firms that are competing for talent. Even if there were, I wouldn't really have been qualified at the time - at least mentally, having taken a job I didn't feel qualified for and making absolutely damn certain I performed well at it made for interesting times, but ultimately boosted my overall confidence a million-fold.
Edit: I would also be remiss to add that at least amongst my peers, colleagues and family, I was doing fairly well. A lot of that had to do with the TN cost of living.
Was it hard to find enterprise architecture position in Memphis?