When you have internal motivators such as passion or dreams, this motivation will never run out and you’ll be willing to fight and sacrifice to achieve what you want. Very few people are going to fight for an iPhone.
Think of the money you earn as your freedom; cash is something you exchange for time off to do things you want to do. So, if you buy a five hundred dollar phone and it took you a week of working forty hours to buy that phone, then ask yourself, was it worth for you to wash dishes for a week or to spend a week of your life in an office so you can buy that phone? For a telephone maybe, since it's a necessity, but could you not have purchased a less expensive version? What about the five hundred dollar jacket or those new name brand sunglasses? Were they worth you sitting behind a computer working for a week? When those items can be left behind at a party, wear out, they can get damaged and become unusable at any time. If you choose to invest some of that money, instead of spending it on things that will soon not be worth anything or that you don't need, then that money can grow through compound interest and buy you more free time. Remind yourself about your purpose in life; you are not meant to be here to purchase and consume products so others can get wealthy off you. You are here to live the life you were expected to live, and if you don't have time, then you'll never learn what that life was supposed to be.
Buy what is necessary and invest the rest. Remember your happiness should not be coming from material things; it's supposed to come from your experiences. When possible, buy used clothes, salvage cars, and aftermarket necessities. This will have a positive impact on the environment and your quality of life.