For the same rig hierarchy, what is the performance difference between a skinned mesh (with vertex bone weights) versus static meshes at each bone I.e. Not weigthed vertices.
Yes, static meshes would be cheaper, since they would skip the skinning pass in the engine, possibly eliminating the skinning draw call entirely.
Effectively skinning will do a weighted interpolation between 4 or 8 bone transforms, which is significantly more work for the GPU in addition to the usual vertex shader.
Whether you want to sacrifice the quality, though (and I suppose this would only be for avatars way off in the distance), you determine by the first GPU measurement in a Chrome Profile.