Generally, when it comes to a large bulk order, the price per model doesn't change based on the amount of models ordered. This is because (in effect) the price we offer is already our bulk price.
Traditional manufacturing requires a specific new process be built for each model. This process has a lot of start up costs that can be mitigated across a larger order but make a single order too expensive. This appears as a bulk order "discount". 3D printing does not change the process for each model and, therefore, does not have the same start up costs. In other words, you get the same bulk discount price whether you order one or one hundred.
You can find out more about Shapeways pricing HERE.