When I was young, pastors preached a lot on materialism. I heard sermons on the evils of jewelry, hair salons, pricey clothing and gold rimmed eyeglasses. 
I have not heard a sermon on this topic in decades, and never have I heard a televangelist preach about it. 
So, what is materialism, is it a sin, and are we guilty? I say that as I type on an IPhone, wear name brand shoes and watch a large television.