I’m a high school student and I don’t want to spend $47 for terrains, it seems pretty pricey and would take most of my money. I know that Unity Asset store has some sales occasionally, and am wondering if I should just wait for a sale to buy it, unless they are really persistent about their price.
Black Friday in November 
I got it for $25 early in November 2015. I’m not sure if that was a sale price or if it just started out cheaper.
Terrain creation tools like World Creator 2 all have academic (educational) discounts, and you could make your own terrains, if you take the time to learn the software. Don’t buy other people’s terrains because then your game will look just like many other games that also buy the same pre-made terrains. If you contact World Creator 2 or other companies with these type of tools, tell them what school you’re a student at. It’s a low-key way for students to get the software at a much discounted price.