The Pirates appear to have a three-year extension worked out with Maholm, but financial terms are unavailable at the moment, so let's project the ballpark figures.
Maholm is 26 and in his first arbitration year, over the last three years (all of which he's topped 170 innings starting) he's been worth roughly 1.95 wins per season. That gives us a ballpark estimate of between 26 and 28 million. However, as mentioned, Maholm is in arbitration, and will be until the end of the extension. Apply those multipliers (.4,.6, and .8) and we have a 16-17 million estimate.
That doesn't seem too far off, and considering that Maholm asked for ~3.8 million in arbitration, and the Pirates submitted ~2.7, I don't think a ~3.4-3.5 settlement is too far off.