The comps unfortunately will not vary since they are usually based on the housing market trends, square footage, and amenities - not a construction technique methodology.
Looking back at the data and cost analysis which I had done for a LEED Home here in Michigan, the cost difference is only approximately 2-5% greater than if the home was not built LEED certified. This is minimal.
Typically this cost increase is not the cost of material but the cost for labor to properly construct the home.
If you are selling your home you will need to market the cost savings due to proper construction and energy efficiencies.
Harold Remlinger, AIA, LEED AP, NCARB DesignTeam Plus, LLC