TerrainCrate is really picking up steam on kickstarter. The set's are a bit pricey, but you get a ton of content. For instance, the Dungeon crate set has 99 pieces for $75 bucks (making it roughly .75 cents per item). This value goes up more when you get a 3 crate bundle (making it .60 cents per item).

Anyway, rather then blather on much longer, here's the link: https://www.kickstarter.com/projects...?ref=user_menu