The Pirates are nearing a deal with Clint Barmes, apparently for two years at roughly $11MM. Though it seems like a somewhat friendly deal for a guy with a career 74 wRC+, it's not a big overpay (if at all). The deal pays him to produce ~2 total wins over the next two seasons, which is less than what he's done over the past four seasons. Depending on your WAR implementation of choice, he's averaged 1.5 to 2 WAR since 2008. I'd say Pittsburgh gave him a slightly more money than he's worth, but considering how the free agent market is shaping up, it's perfectly justifiable. In fact, there's some potential that the Pirates get surplus value out of him.
The real question for the Pirates is if signing Barmes -- at this price -- over Ronny Cedeno was a smart decision. The Pirates had a 2012 club option for Cedeno at $3MM, and chose to buy it out. Barmes is the better of the two, but is the gap big enough to justify paying more for Barmes?
Over his career, Barmes has been the better hitter: .248/.303/.393 (74 wRC+), compared to Cedeno's line of .249/.297/.357 (67 wRC+). Bill James projects Barmes to out-hit Cedeno in 2012 by about 20 wOBA points; it may not seem like a lot, but that equates to an extra 10 to 15 runs over a full season, which is obviously significant. Additionally, Barmes appears to be the better defender -- though it ultimately seems like a wash. 2011 was Barmes' first full season at short since 2006, and though he rated well, Cedeno was the better defender if you go by FRAA.
Ultimately, Pittsburgh is paying more for a better shortstop, and -- at least in 2012 -- Barmes will probably give them more bang for their buck than Cedeno would have. But taking into consideration the Pirates' needs, they would have been better off exercising Cedeno's option than handing two years to Clint. It makes more sense for the Pirates, a team that has not had a winning record since 1992, to go with the cheap stopgap. They simply have better ways to allocate their money, considering that they're not built to contend right now. And Cedeno's not so bad, really -- especially if he can play above-average defense at shortstop once again next season. Barring an injury, he should be good for +1 wins in 2012.