When I find that I am falling into the trap of emotional highs from buying crap I don't need, I just remind myself that I grew up with only the essentials and I don’t need more toys. If we (my siblings and I) wanted anything, we made due with homemade cardboard props (for the USS Enterprise (NCC-1701)), sticks for swords, or paper men for armies.
It sounds embarrassingly crude, but it has served as an internal equalizer when I feel like desiring or whining. I have tried to demonstrate to my kids that contentment (happiness) is really best obtained and empowering when you realize you don’t need to buy it, you can just make or generate it yourself.