Books in Mexico are indeed expensive, and not only in relative terms, but also in absolute terms: A thing paperback will easily go for 20-25 dollars, with much left wanting in terms of editing and organization. That does not stop me from spending way too much money on books on Mexican politics.
Two news ones I just went through: A biography of Marcelo Ebrard, and an auto-biography of Carlos Navarrete. The former I do not recommend; the latter I do.
The book by Alejandro Páez Varela on Marcelo Ebrard is not really that bad, and does offer some new insights on Ebrard, especially his trajectory in the 1990s. I did not know, for instance, that he went with Cárdenas in 1988, even if he stayed in the PRI, and the book also reminded he that he was an outspoken opponent of the FOBAPROA bank bailout in the late 1990s - something that likely endeared him to AMLO.
But the problem is this: There are too few sources, and the books is simply too thin, with large font, and virtually the entire book is printed elsewhere! That's right, as a chapter in the excellent edited volume Los Suspirantes by Jorge Zepeda Patterson, by the same editorial. Rip-off alert, indeed - and the chapter in Zepada's book is even better, as it has removed some unnecessary self-promotion by Páez' own projects. One additional weakness is that in the book, Páez lets his interview subjects simply talk, and presents their criticism of Ebrard (or praise) uncontested - there is little analysis and attempts to actually confront what they are saying, or corroborate their claims.
The second books is bye Senator Carlos Navarrete of the PRD, entitled De Frente. It is also pretty thin and clearly written with Navarrete's failed bid to be the lefts candidate for Mexico City in mind, but it is nonetheless a highly enjoyable read of Navarrete's political life, and includes some very interesting material on the Mexican left and the PRD. Did you know, for instance, that the PRD's parliamentary coordinator, ahead of Calderón's acceptance speech-ceremony in the Chamber of Deputies, which the PRD sought to block, had to make a last-minute desperate search to locate tear-gas granadesthat some deputies were planning to hurl during the ceremony (with likely injury and loss of life)? The coordinator, Javier González, successfully located the grenades, and stored them in his own car outside of congress...
There's also much more good recent material here, such as the 2008 oil reform of PEMEX, and AMLO's ridiculous blocking of a reform that his own advisers had largely drafted. Go and read it.