Don't bother buying anything.
Here are some references (all can be downloaded - Internet Archive references in multiple formats):
ALBC Turkey Manual (focuses on pastured turkeys but concise info on most subjects): http://albc-usa.org/downloads.html#turkey
Internet archive sources (though the treatments of certain diseases/feed choices have changed, the info in these older references is otherwise thorough). There is more turkey info in the archive so try searching!
Turkey fertility (UC Davis): Good explanations of what causes various problems observed in newly hatched poults/very complete guide to artificial insemination (though no info on vent sexing of poults):
Turkey Diseases (UC/USDA): http://archive.org/details/turkeydiseases03hins
Turkey Raising: Lots of detail/ancillary info: http://archive.org/details/turkeyraising00lamorich
If the need arises for in depth info on emergency med/etc.: Harrison's Principles and Applications can still be downloaded by chapter at his new business:
(this used to be available as a single download. It's very good and, though focused on parrots, fairly comprehensive - don't know how long he'll continue to allow downloads by chapter - get it all if you have a fast connection).