actually the last LOD should be far less than 300 triangles.
you really don't need details, the LOD3 model is used just to give something to render in the few pixels of the monitor used at its render distance.
and - believe me on this- 3k polys is far, far too high even for lod1.
The point is that this way you reduce a lot the gameplay, LODS are intended just to increase gameplay, for models without much details or high res textures, that will be useless at the distances they are rendered.
A model of around 1k triangles will be even too much for a lod1.