Different things are important to different people in life.
When it comes to shopping, I'm sure we have all been frustrated when we've missed something we had our eye on... but unless QVC is the only source for something and it's out of stock, why fret about it? Shop elsewhere and discover whether you can get better service or prices for the same items. You might be surprised.
Unless it's a warm safe place to sleep, and food and drink to keep you going, or medication to treat specific ailments, there is not really anything we "need" enough to be lamenting on social media. Unfortunately advertisers and retailers thrive on generating in us a sense of dissatisfaction which can be satisfied by using product X or buying product Y. They create a demand for something which is not necessary, but which they have convinced people they need. We've all fallen for it at some point. But the truth is that the well of dissatisfaction doesn't get any smaller, because they've moved on to identify another "gap" in your life that can only be filled by a purchase.
I sometimes feel myself getting into that feeling of "I must get..." but if you wait long enough before rushing to buy, you find the feeling dies down, and common-sense prevails.