Smaller, yet more expensive?

I apologise if I've posted this in the wrong section!

I've recently uploaded a file with a model I was hoping to get printed, though before I added a texture, I uploaded the .Obj file to see the approximate price. However, I'm very confused right now!

The price it quotes me is around €50 for a 2.5" model. However, someone has a model up with even more detail than mine, a larger size and they're charging only €17 for it in Sandstone - Any ideas why?

My model is hollow, and I don't believe it's all that detailed in comparison to many of the models that are larger and somehow less than half the quoted price for mine. Is Sandstone somehow cheaper than the other options? Thanks for any suggestions.

If you look under the "Materials" tab, you will see that the "sandstone" has twice the fixed startup cost of "strong&flexible", but its per-volume price is
about half that of "strong&flexible". ($3+$0.75/cm3 vs $1.5+$1.4/cm3) . On the other hand, "sandstone" parts need higher wall and wire thicknesses and cannot have heavy or extended overhangs due to the more complicated production process.
If you want your object to be textured, you will have to choose sandstone anyway (no price difference between multicolor and "plain" sandstone).
Either you mistook the first price quoted (probably for strong&flexible) for the sandstone one, or your model is not hollow anymore due to shapeways'
software attempting to fix a flaw in your model. (Or units got mixed up somehow, and your object is now 2.54 times bigger than planned - the model page will show you both material volume and dimensions)

And another option - unless the 17 Euro part you compared to was actually printed (or at least is on the pages of a clearly experienced designer), it could simply be that that model has too thin walls to be printable in sandstone. (Thickness checks are manually done at time of order. The more detail - not texture - the less likely that it was intended for sandstone at all, maybe the designer just neglected to remove sandstone from the list of choices).
Hard to guess more without even a rough idea of what your model and the 17Euro one in some shop look like.

Thank you for your response. I have fixed up my model and I'm hopefully in the process of getting it printed at last (I'm just waiting to hear back from Shapeways, as my uploads don't seem to be uploading correctly).

Thanks again!

Not uploading at all, or looking wrong/incomplete after upload ? Their site software does an automatic cleanup of files that tries to fix common flaws - sometimes that will result in holes being closed where there was an error in the rim, or small parts being removed if they were not attached properly.

They look incomplete after uploading. But what I'm not understanding is that when I re-upload the original file - Which did upload correctly and hasn't been modified since the original upload - That also displays flaws which weren't there on the previous upload. Also, all of my models suddenly display as 0.2 inches (height) regardless of how I modify their size.

I'm just curious on if the system has maybe been updated last week?

Have you tried viewing your model in netfabb studio basic (freeware) ?

I've just downloaded the program, and viewing the model in netfabb studio basic shows the model as having no problems. The model dimensions shown are also more accurate (if that matters any).