Is it normal for homeowner's insurance to increase each year?

…or is my agent trying to pull one over on me? My homeowner’s insurance increased from $1400 to $1800 and the way I found out was from my mortgage company. I called and asked questions as to why this is and my agent “did me a favor” and dropped it to $1600/yr… still $200 more. He says the increase is because of increase in cost of lumber and other building materials, so he has to up the amount of insurance on my home so that if something were to happen they could rebuild it. Does anyone have any knowledge of whether or not this is legit? Or should I shop around for another insurance company? I am in Mississippi and my insurance company is Alfa, if that makes a difference.