These guys are pretty good.
http://www.propublica.org/article/setting-the-record-straight-on-ges-taxes/single
But the article you sight says “but the words “tax benefit” are so ambiguous that it’s not clear what they mean,” If Palin is referring including federal grant money into the equation then she is correct, and she states that Federal grant money in her article. Apparently the term tax benefit is ambiguous rather than a term like net profit.
On the whole I liked the article and I think she is delivering a solid conservative message. I don’t think we should split hairs over a ambiguous term and loose sight of the salient points.