Both the Suchet book and the Laura Thompson biography were only .99. I'm pretty sure that my fellow Agathytes who have read Thompson's biography were underwhelmed - remind me below.
I also decided that if was going to embark on a project of understanding Christie better, it made sense to go straight to the author's own words about herself and her life, so her autobiography is the thing that I plan to concentrate on first.And the Curran book was really just bought on a whim because the premise is intriguing, especially now that I don't have to worry about any of the solutions being accidentally spoiled.
Which takes me back to A is for Arsenic, actually. I own it, but was reluctant to read it because I didn't want to spoil any of the unread books.