Two of my favorite 3D folks printed from Shapeways in 1:20 scale. At this size you get some great detail in the cheapest print medium. They are still pricey but what can you do? I’m working on molds for resin casts but they are an art form themselves. Raspberry Pi in the background, pencil in the foreground for size.

They are here:
http://www.shapeways.com/shops/blueridgeengineering