Guaranteed, Billy Beane did the math on the trade and the Athletics "won" the trade on paper.
Lawrie and Donaldson are on the opposite sides of the aging curve - Lawrie should be just entering his prime while Donaldson is just exiting his. Without making any improvements, Lawrie is one of the best 3B in baseball - a gold glove 3B with contact skills and 20 HR pop. Of course, the extent to which you think Lawrie's health is a skill / an inherent trait changes how much exactly that will ever be worth to a ball team.
It's easy to dismiss Graveman and Nolin as 'meh', but they have significant value. They hold much more value right now than, say, most first round draft picks. I think they are both starting pitchers. Nolin for obvious reasons - and I loved Graveman's stuff when he was up. Kind of a Henderson Alvarez profile.
I think Barreto is being very overvalued in the common deal analysis though. A teenager in A- ball who, by near consensus, won't stick at shortstop... I dunno. I get the impact than an up-the-middle guy with with 5 hit 5 power 6 run could potentially have, but the profile isn't other worldly and he's a few years away from doing anything. So much can go wrong.
Donaldson is the best 3B in baseball and he's probably a top ~5 player overall for 2014. When was the last time a player like that with 4 years of below market control was dealt?
This is what Oakland does though. In order for them to compete, they absolutely have to be in a constant mode of selling high and buying low. The only real obfuscating factor here is that Donaldson isn't much more expensive than Lawrie, or any closer to free agency. That's the weird part.