For BPavel and others who may not know, Blender is a free open source polygonal modeling package. Consequently, just about any 3D modeling or CAD software can be used since all one would need to do is export an STL and then import into Blender to save out from Blender in Blender's native format. I don't think the buyer needs anything but an STL though since he has mentioned 3D printing. However, the buyer may want to make renderings using Blender and that may be why the buyer is requesting Blender format.
In the description, the second sentence appears to be cut off. Is that a typo?
"We're not looking for a troll, or a dwarf, or a smurf, or an elf, or Santa." I see I see. In addition to this description, have you seen anything out there in the world that has a general feel for what you're looking for? Well, let me rephrase that, I doubt there are any modern looking gnomes out there, but what do you see in your mind's eye when you think gnome, can you find a reference image or two you can show us? Thanks.
Gardener
Buyer