I am a big fan of the Clancys and Tommy Makem, but I'd have to say that to me the book would be a bit of a disappointment to anyone who isn't a avid fan of them. There are other books about life in Ireland that are similar enough, and better written that can be suggested. I had hoped that more stories about what happened after they made it big would have been nice. But this was a "How I (we) got there" story - not a complete biography. More stuff, like is in the Chieftains bio would be nice.
I'd bet that Makem could write a wonderful book if he ever got around to it.
You can get it used online at Amazon or Half.com too - I paid $2.50 plus book rate shiping for a "like new" used copy of the book.