The secret to minimalist living in terms of letting go of one's desires lies in orientation towards inner freedom rather than financial freedom. So instead of asking "can I afford this?", which is bound to monetary resources, you should ask "can I afford to live without this?". This paradigm shift frees you from depending on external circumstances to feel good and leads you to true happiness.
By the way, this mindset enables you to get off the consumption treadmill for good. So if your goal still is to become wealthy - adopting a minimalist attitude is first the step in any case.