Hey buddy you have some very nice blendfiles there, good for rendering and so far I can say all looks professional. Unfortunately blender is not the the preferred standard, but just give it some time, things will change ;) . Just convert your blends to fbx, obj and dae or other 3d-formats, the more 3d-formats you have the higher the possibility is sale something. And if a 3d-format does not works well, the customer will tells you, you find a solution and
learn something about how to export it correctly (true story) :)