Isn't 3 million a year about the price for a 4.50 ERA from a lefty who can start or relieve?

Sure, the mean expectation for Rusch might be 4.50 (I'd quibble and say closer to 5), but the problem is that there is so much variance around that mean.

Isn't 3 million a year about the price for a 4.50 ERA from a lefty who can start or relieve?

He's the sixth best starter right now and might be the third best lefty reliever in the organization behind Ohman and Rich Hill.

He isn't even particularly effective against leftys (.758 OPS since 2002, all I could get from ESPN) which makes him even less useful as a reliever.

The Cubs really don't have a spot for him. Jerome Williams is no great shakes but I find him preferable to Rusch in the rotation. He is an expensive insurance policy and might even becomes rendundant in such a position because Chicago is talking about fiding another starter on the market.

The contract might not be a poor investment for a team that would actually use him in the rotation but I'm not sure what use the Cubs will be getting out of Rusch. It's a roster spot that could be used for a better (in a relief role), younger pitcher in Rich Hill. A fine signing for the Rangers but I don't see it that way in Chicago.

That .758 OPS against leftys is only for 2002-2004. In 2005 he put up a .909 against that group.