I’m going to sell my M&P40C. It has a Law Enforcement SKU (307703) and is in the large M&P Black box; that apparently isn’t available anymore. Do these bring a premium?
Used 40C's are selling for $350-$425. I doubt there is anything that can increase their value, particularly with the large number of police turn-ins on the market.
Having the original plastic box is a plus when selling. It doesn't really have a dollar value but it tells me the owner probably used it for storage and not some box in the basement. Just supports your price.