There you go. Set the "sales" tax rate on a luminous efficacy sliding scale. The lower the efficacy, the higher the tax %. It'd have to be some kind of wholesal

There you go. Set the "sales" tax rate on a luminous efficacy sliding scale. The lower the efficacy, the higher the tax %. It'd have to be some kind of wholesale/manufacturer tax, at least in the U.S., so that it's reflected in the sticker price before checkout.