Is it necessary for an ATPL(A) exam? Maybe some of the questions are specifically related to enroute charts and approach plates contained in GSPRM, idk. I have the most current Jeppesen General Airway Manual plus a few DVD's as my main information source about jepp charts. Can I get along with it?
With good books and AVExam you can avoid buying it.
If your NAA allows you to use it during the exams it would be wise to have one, so you can just read definitions, minima and legends. In Italy you're not allowed to use it and you only get a copy of the charts.