Yeah it is expensive ("Gut Reactions") because it hasn't come out in paperback yet. I'm not sure about buying it... Prinz is interesting at providing a 'big picture' view which is interesting, but some of his arguments aren't very carefully articulated or well thought out. You can download sample papers from his homepage:

http://www.unc.edu/~prinz/

(Click on 'research' then scroll down...)

There is a paper on emotions that summarises his view.
Bodily change theorists (James, Lange, Damasio) have trouble explaining how emotions get to be about things in the world.
Cognitive theorists (what used to be the mainstream view in philosophy) considered this to be a fatal objection.
Damasio backs down and says emotions are bodily states coupled with judgements.
Prinz tries to say that Damasio didn't need to back down to there. He attempts to explain how body changes can be about things in the world.

His book does all this in a lot more detail, but it will give you some indication as to whether you are likely to find it interesting or not...