I can understand wanting to avoid hagiographies. I think they are wonderful, wonderful things, and of great benefit to read. But after a while, especailly if you are reading a collection of martyrs or something, it starts to really drag out and get tedious and difficult. Plus, people in modern society are much more interested in the biographical details than people were in previous times. I do think that "Biographies" have some problems, though. I've read a couple now which seem to try and be accurate, but came off having just as much a bias as any hagiography (sometimes to the benefit, sometimes to the detriment, of the subject).
I did a search for the book Prodigal Saint: Father John of Kronstadt and the Russian People, but unfortunately the price does seems to go about $70 hardcover ($25-27 soft cover) everywhere on the net.