When you improve the material a little bit, the package could be worth the price. 
But I personally would add more and different types of landscapes (probably one with hills, something like an island, a sand desert scene,…) to the package, because with world machine or terresculptor those landscapes are pretty easy to generate.
But as I mentioned, just use a similar setup like in the starter content material (especially the grass material) -> will look much better 