So who wins the A's/O's closer trade?

With the Orioles signing erswhile Athletics closer Grant Balfour to a two-year contract, those clubs have completed a sort of challenge trade, with ex-O's closer Jim Johnson going to the A's in a real trade earlier this winter. This made me scratch my head a little, since qualitatively they're the same pitcher and the A's are paying more for theirs. Here's John Hickey asking the obvious question:

So who comes out ahead here? The A’s have to pay Johnson more (he’s likely worth in the $10 million range in salary arbitration) for less – he’s a free agent after this year. The Orioles have Balfour locked in for two years for less – just $14 million.

The late 49ers coach Bill Walsh used to like to say it’s better to trade a player a year too early than a year too late. And while replacing Balfour with Johnson isn’t a trade in a traditional sense, the A’s have swapped a closer who will be 36 in 2014 for one who will be 30 when the season starts.

--snip--

If they both have good years, it’s a wash. If they both have bad years, ditto. The difference is that the A’s are grooming Ryan Cook, Sean Doolittle and Dan Otero as possible closers, so Oakland will be ready in 2015 if a change is needed. Baltimore will have a second season of Balfour if things go south.

If they both have good years it's not quite a wash, because the Orioles will have paid less for their good year and they'll be set for another good year, probably. But the difference between $10 million and $7 million is essentially irrelevant in today's Major League Baseball. Yes, I would have preferred Balfour for 2/15 over Johnson for 1/10. But a) the A's might not have known Balfour would be available quite so cheaply, and b) again, the $3 million difference in AAV is barely worth mentioning.

I think there's a bigger, more relevant question lurking here, though ... Why are the A's spending $10 million any any relief pitcher? You might make an argument for Craig Kimbrel or Greg Holland. Maybe Joe Nathan or Kenley Jansen or Koji Uehara. But $10 million for a good (but not great) relief pitcher? When Ryan Cook and Sean Doolittle and Dan Otero and probably a few other potential closers are sitting on the 40-man roster?

Billy Beane used to tell me it was foolish to spend big money on relief pitchers. But a few years ago, the A's did an about-face after apparently concluding that relief pitchers were the new market inefficiency. So they signed Balfour and Brian Fuentes, even though Andrew Bailey was already their closer. Fuentes struggled, but Balfour took over when Bailey left. But Fuentes signed for roughly half what Johnson's going to make. Balfour a little less than that, even. I don't think the A's have ever come remotely close to paying a relief pitcher $10 million for one season before. And I have absolutely no idea why they would start now. I would rather have paid Balfour $7 million, and I would really have rather paid some kid a million and found a better use for the rest of the money elsewhere.