Material Costs vs Scale

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.

WSF and family have some extra pricing rules for big objects that use more than 10% of the bounding box. You'll have to search for that, the materials page lacks it... try the blog.

Assuming you scaled the model by 2 in all three dimensions, the new volume should be 2x2x2=8 times the previous volume, so the sandstone price looks right, and the WSF must be discounted because of the larger size.

Thanks for your replies!
I understand why the cost is different now.

Hey TinBane

I will update the material page asap

but the deal with WSF is:

# On a White, Strong & Flexible model you will then pay the regular $1.50 per cubic cm for any model that is less than 20 cubic cm as well as a start up fee of $1.50 per model.So no change there.
# On White, Strong & Flexible model larger than this you will pay a start up fee of $1.50. You will also pay $1.50 per cubic cm for the first 20 cubic cms. Any additional cubic centimeters are only $0.75 per cubic cm.

Or you could say WSF from 75c percm3*

*plus start up costs

Cheers

Yes you ar right Drscott, we could say that for dense object of more than 20 cm3, you pay a start up cost of $31.50 (for the first 20 cm3) and $0.75/cm3 for any cm3 exceeding the 20 first ones... It is perhaps easier to understand (or isn't it? ).

It's easier to think of it as a startup of $16.50 + $0.75 per CM3.

Yes, you are right. As long as it is more than 20 cm3 (and has a density of more than 10%, of course).

Found it, Price Reduction Offer. Basically half price for centimeters beyond first 20, if the item is dense.