It never ceases to amaze me why individuals are so parsimonious when it comes to acquiring pilot kit. Everything comes down to money, of course, but those who insist that a PPL can be studied for and passed with just a pencil and piece of string, just plain confound me.
If you've got the money, what on earth is wrong in kitting oneself out appropriately?
Study packs are absolutely fine. In fact, many schools recommend them as it standardises the kit their students use and prevents confusion when the student is passed from one instructor to another, who have conflicting ideas as to what kit one should use.
Headsets and sunglasses aside (both essential items, IMHO), don't go and buy your kit off the Internet. Instead ask your school to sell you the kit. Most UK schools (can't answer for the US) stock training material (including study packs) and will be happy to sell it to you at standard retail, netting themselves a small dividend in the process. Support your school!!