Since you know it is cyclical I find you can simulate the experience of being over something you are temped to buy before you even bought it. You have seen the pattern over and over you can map the prior experience of getting over an old piece of junk to the present junk you are temped by and kind of get over it in the instant that you are enticed by it.

You see the object and you are enticed by the idea of the initial satisfaction, the thoughts of what you will Initially do with the object, but if you consider the future beyond that, you can think about the object taking up space in you closets, or the time a year from then you will regret the money spent on it because you never use it again. If you consider the potential of that occurring with each purchase you can mitigate the initial excitement factor and make more rational purchasing decisions.