This isn't some baseless rumor, folks: It was tweeted by a 13-year old. Though the rumored trade talks around Brandon Moss don't fit this pattern directly, there is much precedent for the A's seeking "younger cheaper likenesses" for their increasingly aging and/or expensive players.
Even Moss may have a shadow-double in Ike Davis who, while lacking Moss' raw power, could replace much of Moss' overall value against RHP at half of the cost and the right side of 30 years old. However, Moss will not be dealt directly for Davis, whereas historically A's players have often met their shadow-doubles entering the clubhouse as they exited.
You can go all the way back to the trades of Mark Mulder and Tim Hudson, when Oakland dealt Mulder for a young Danny Haren, who would emerge as a top of the rotation SP and swapped Hudson out for the highly touted Dan Meyer. Had Meyer stayed healthy and met projections he would have joined Haren to be the "big 2" replacing Mulder and Hudson.
Haren was Mulder-lite (but wound up better) and Meyer was Hudson-lite (very, very lite) and the pattern persisted when Trevor Cahill was shipped to Arizona for a young, projectable SP in Jarrod Parker. Parker almost immediately assumed the role Cahill had recently held towards the front of the A's rotation.
Josh Donaldson was just sent to Toronto for his shadow-double, the younger and cheaper Brett Lawrie: A right-handed 3Bman with some pop in his bat who can be a whiz around 3B. In fact Lawrie was once touted as a far better prospect than Donaldson, suggesting that the difference between them is not skills so much as age (advantage: Lawrie) and who has better tapped into their potential so far (advantage: Donaldson). In this case Oakland is banking on the difference in age to bridge that gap; perhaps Donaldson starts a downward trend just as Lawrie is surging forward.
Of course there are exceptions. There have been another set of deals that have been about swapping known quality for a spread of "best prospects available". You could argue that Tommy Milone was a lite-lite-lite-lite version of Gio Gonzalez, but in reality Gio was a front of the rotation SP and Milone was never projected to be more than a back-end SP, so really all they shared was a propensity for throwing left-handed. The Gonzalez trade was about getting the best prospect haul back the A's could.
So was the trade that sent Danny Haren to the Diamondbacks. Yes the haul included Brett Anderson, who had "#1 SP" potential, but Anderson was 19 at the time and was not going to replace Haren in any direct way (as Parker did Cahill). The A's just got "a heck of a haul". Same with Nick Swisher to the White Sox for Ryan Sweeney and two exciting SP prospects (Gio and Fautino De Los Santos).
In sum, Billy Beane appears inclined to make one of two kinds of deals. Either he approaches a trade like the draft and "rebuilds" by seeking "best prospect haul available," or he targets a double-shadow as the centerpiece and tries to "reload" by getting "younger and less proven" in one area in order to get additional pieces or create payroll flexibility.
That's how you can distinguish a "rebuild" from a "reload". The Mulder and Hudson trades were part of a reloading, which paid dividends in 2006. Gonzalez and Swisher were part of a rebuilding that took until 2012 to come together.
Note that the signing of Billy Butler does not tell you anything. Beane has made similar signings throughout both phases. I think the idea behind a Butler-type signing is that "a good deal is a good deal" because a good player with a good contract can either help you compete or help you by being dealt to a contender. Also, for better or worse the A's do not punt seasons entirely, preferring to win 76 games in a bad year rather than 60 games.
So Butler was signed not because the A's do or don't intend to compete for the AL West in 2015, or 2016, or 2017, but rather because he is a good player to have for the contract he signed. He will help the A's win more games or he will help the A's have more useful trade chips down the line.
As for me, there's a student in the 7th grade who kind of reminds me of "a younger me" ... Ruh roh.