want vs. need

I wrote in my moleskin journal about this a year ago when I was in the mountains with my family.
I want to do an analysis of want vs. need in a materialistic setting, but also explore want vs. need in terms of the human condition.
We all want things in life, and more often than not, the newer the better. So how does this mindset come about? What does psychology teach us about ourselves when determining what we want in life? We want cars(new and old), cameras(new and old), toys(new and old), houses(sometimes old and new), instruments(sometimes old and new), computers(definitely new, but sometimes old), etc. So what separates wanting something new vs. old? Personally, I think it's aesthetics over actual functionality. You don't want an old Apple II computer so you can run Adobe CS4 on do you? Of course not, it won't even work. You want that computer so you can feel nostalgic, embrace the time period it was invented in, collect it, or even sell it for profit for more things you may want. We want new things because we think they will serve us better and help us handle life better. Cars? You better believe people want the latest and greatest models, but there are also collectors that want old relics because they think they aesthetically look and feel better. But what about wanting happiness? Wanting comfort and stability?
Getting back to why we want things in life... We want things because we think they will make our lives easier, happier and in more control. We are almost always striving to want to become better humans, to want to fit into society, etc. This is not true for every human, as their ideas of want in the categories of improving upon self and materialism never meet. Sometimes, people that don't want to better themselves as humans are mentally disturbed or they are just incredibly lazy. The general consensus of what humans want in life is to become better. So do we want material things to make us better humans, or is this a selfish desire? I think this is a little of both and this is also where you begin to see want vs. need bleed together.
You need only a few things in life to actually survive as a human being. You need food to live, shelter to protect you from the elements, sleep, and... well, that's really it! I could expound upon that by saying you need happiness and laughter to stay sane, but these are not material items. You also need in your shelter electricity to see, gas to stay warm, etc. Do you need a car and transportation to get that food? Yes and no. You could walk to wherever you are going, but that takes time, and also places stress on your life, which may eventually cause you to be unhappy, and even more, possibly depress and kill you. This is a pretty broad statement, because one can obviously live as a homeless person and possibly be happy. More often than not, these people are sad, lonely, and long for a better life. Certain spiritual non-materialists only want food and shelter, but also maintain that they are bettering their relationship with God or a higher power by doing this. You don't need a car because you can take public transportation. You may or may not be happy or sad with this, but from the looks of it, you need public transportation and travel(depending on your region). Some people don't have cars and are completely happy. This is where want vs. need becomes a little blurry because want vs. need is also affected by culture and our surroundings.
Let's get a little deeper... if I'm beginning to see a need for certain things in life to keep me happy, does that make me a better or worse human being? This gets even fuzzier, because this is where spirituality can kick in. I may have everything I could possibility want and need in the world, and still not be happy. You see this with many successful business men, who in turn, kill themselves. For me personally, I don't need much. I need shelter(my home that I bought, or an apt or house I could rent), my car(to travel to my place of work to earn income), food(bought with income), friends and family(to stay happy and sane) and God(to challenge my continuing search of purpose in life). This is different for everyone, but that's my list of actual need vs. want. It's not much is it? To me no, but to a monk, it's probably a few more items than they would have on their list. All of the other income I have left over is essentially disposable and can be used for things I want. My main area of focus here is God, family and friends - relationships. I want and need that, and it works quite well saying you want and need this. It's not selfish stating you want it and you obviously need family and friends and God(need not apply for atheists) to survive and be happy. Do people live without family, friends and God and not need them? Sure, but I think they are only kidding themselves, because you need relationships in life.
So how many people think about this in their life time? I have no clue, but I wish more people would think more openly about this. It's a little bit of a scatter brained post, but I just wanted(pun intended) to see the difference between want and need and to see if they were interchangeable and to what extent they are interchangeable.