I’m planning on buying books from the seniors that are leaving my school however they all have different editions for sat prep books sub2 subject tests and ap books. Does it really matter?
Yes it matters. It’s probably fine to buy subject test books if they were published in the last few years. I would not buy any SAT or ACT prep book published before 2016, especially not the SAT guide. And I personally would absolutely get the most recent editions of the both official study guides from College Board and ACT. There is no substitute for the real thing.