An SKS-D is worth no less than a standard SKS. There is a finite supply and unlike a lot of other rifles, these have a market floor value. My concern is they were commercial quality not military quality, ie made to sell, not made to be used in battle. The one l had and quickly resold was not repeat not an exemplary rifle.
When posting for sale, be sure to indicate stock has been painted or sanded down or if any metal has been modified. Every change from original will bring down or hold down the price.