I previously posted a thread regarding the handbook but forgot to mention the ebook
I didn't buy any of them and I know that it's a waste for me to get the handbook
but now this "ebook" do I need to get one?
because I hear people (including TA and Dr.Kim) are saying the material from the ebook are going to be tested on midterm and exams
so for any upperyears who took the course do I need to get an ebook?

The e-book is a new feature added to the Psych course this year, so students in upper years wouldn't really know about it. However, I would strongly suggest getting the e-book, especially if it says that you will be tested on the material. If you don't feel like spending the 30 bucks on the e-book, you can do what I did and split the cost with a friend and just share it.
I also would say that the handbook is necessary too as it has the course outline, due dates & practice questions which I'm pretty sure will come in handy when it comes to the midterm and exam. But, its all up to you!