It depends on several things. First, if the book had anything to do w the crime, absolutely not, no I wouldn't buy it. Second, what crime they were convicted of. If someone w no prior conviction were convicted of protesting near an area designated as a "no free speech zone" by the secret service - I am not sure I would feel they belonged in prison to begin with, so buying thier "product" would not bother me . And, third, where the proceeds go to. If all of the proceeds go back to the taxpayer in some manner (e.g., all goes to prison budget), then - maybe. The thing about prisonors is they are suppose to "pay a debt", which is feasable if they are making license plates or what not. But, as it stands - most imprisonment costs society enormous amounts of money per inmate.
This particular inmates "product" - no, I would not buy it - for the same reasons described by faceman, above.