The joy of simple living

Was browsing through the book "The joy of simple living" in the book fair. One of the rules is to ask ourself 6 questions before we buy something. The questions are something like "Do I need it"?, "Do I want it?", "Does it add value to your life?", "Will you feel very happy of having it?", "Is there any alternative?", and I can't remember the last one... I didn't buy the book at the end after I asked myself the 6 questions...I probably know how to live a simple life already, it is just a matter of practicing it. Just like you know exercise is good for health, but you just didn't do it, just like you know sleeping early is essential for a good health, but you just stay up late everyday. As it is always is, saying is much more easier than doing it.