Welcome to MobileRead, Shibito!
Not to scare you but, if you are anything like me, a reader won't save you money. You'll end up buying more and more to feed your ebook habit!
I love having a dedicated reader and the ability to carry a huge amount of books with me where ever I go. There are a lot of free ebooks here that you can download and more and more local libraries are offering ebooks for you to download. Good luck making your decision. Which ever way you go, I know you will love your reader.
Happy reading!