These are the 5 platonic solids to be used as dice template.
You can download them freely and modify them.
If you want to order this set of platonic solids as they are, there is no markup: you just pay for material and shipping.
In order to reduce the cost, they are hollow, with a tunnel joining the internal shell to the external shell. This tunnel is meant to prevent the automatic repair tool of Shapeways from removing the internal shell. But it is small enough to be invisible and to keep the support material inside.
The thickness of the models is 1.5 mm which is thick enough for Strong and Flexible materials, Details materials and Alumide.
A Youtube tutorial on how to hollow a die
is also available.