I mentioned before that there's been some learning involved in using PinShape. Because PinShape partners with Sculpteo to print your stuff, understanding how Sculpteo prices their prints, which is similar to how Shapeways prices their prints, is key in bringing prices down.
First of all, a big print is a big print. There's little to nothing that will bring down the price of a huge model no matter what you do. Yes, making big objects a thin (2mm) shell and giving it a hole to drain build material is one way to bring costs down, but I don't know any way to make my dice tower any cheaper. But there are tricks that can help my other models.
The cost from services like this is a per-volume cost plus + setup fee. So if your thing is made up of a lot of different parts and you print them all separately that setup fee is being paid on each part and ends up adding up quickly. But if you don't mind if those parts are all printed with the same material, placing your objects in one model file with enough space between them that they don't fuse together (about 2mm to be sure), a practice called "plating" on FDM printers, will save significant amounts of money. How much? Let's find out.
Doctor Who pawns I uploaded them ala carte, as 12 different models. When uploaded that way the cost for printing them was a whopping $66.51. This for a handful of small pieces of plastic. So as an experiment I put all the individual STLs on a plate setup that would still 3D print happily and uploaded that and the price dropped to a considerably more reasonable $13.92.
So there's clearly advantage to be had in pre-plating files, but less advantage in alienating home 3D printer folks. Which is good. So with this new understanding I've gone through and, where it made sense, lowered the price of many of my PinShape models. Hopefully, maybe, in the future PinShape can do the plating for you and save you money or multiple items you want to order.
But that dice tower will forever be pricey.