First of all, your thesis statement is specific since it precisely indicates what the plan is about. It is direct to the point and this is fundamental because it gives you an opportunity to successfully verify your argument. Additionally, it is argumentative in nature. On the introduction part, I think you could have introduced the book, its authors and generally summarize what it discusses into details Moreover; you could have summarized about the concept of materialism/consumerism as it is discussed in the book.
I like the way you have presented the first effect of materialism. Your introduction of this effect is informing. The evidence from the book is correct and good since it even stresses how we spend a lot of money on things that are not essential by giving statistics. Your explanation is perfect since the audience directly understands this cause. Nonetheless, you did not provide another evidence from Affluenza as it was required and also personal evidence. Therefore, it is important that you incorporate them in your plan to make it more informing.
On the second effect, you have accurately described how we are spending extra time at shopping centers buying things that are not necessary. In addition, the evidence from both Affluenza and personal experience is sound as it directly supports the effect you have presented.
The third consumerism effect looks good since you have extensively described it. Nevertheless, you need to cite two evidences from Affluenza and one from your own so as to make the audience comprehend more.
Lastly, on the possible solution part, your topic sentence is perfect as it proposes what we must personally do. The evidence you have provided is correct since it suggests that the solution to materialism/consumerism lies in our hands which is true. In a nutshell, the plan is generally good, but if you will incorporate the suggestions that I have made, it will be perfect.