So I am planning on getting the Tevo Tornado in a few days/weeks, and I am trying to calculate costs for things I’ll need besides the printer itself. I know that a 1 kg roll of pla is approximately $25-$30. The first of my questions is how long does that last, on average? Also, does anyone know of any cheaper rolls that are still reliable*? And my last question is what else might I need/want to have a good start in 3D Printing?