I'm creating a model at the moment, still working on the design. I've uploaded a copy which is about 10cm on it's longest axis. The cost for the model at 10cm is $ 14.70 WSF, $ 10.21 for sandstone. Which intuitively is correct, because sandstone costs 2/3 for materials, plus the surcharge to start with. However, if I upscale exactly the same model to 20cm, using the same blender file and exporting it out the cost comparison changes. The cost for the 20cm model is $ 69.24 WSF, and $ 71.12 for sandstone. Is there a cost to exceeding a certain scale in sandstone? I thought sandstone was recommended only for larger scale models? Or is it a bug in the calculation? Sandstone should be around $45, assuming the WSF estimate is correct.