I agree with rampart that it's always good to see if you need a terrain at all. Just like in the old film studios, you can do things with 2D backdrops which can even contain video. I do use terrains for outdoor scenes that are not flat and when there is movement through the terrain itself. There are terrains for sale, but they don't always meet my needs. Also, the texture quality of some of the older terrains from before IC5 is not up to current standards.