I am sorry I dont see a demand in your listing. You have a valid point about dealers low balling the price of the car but then again thats a universal fact.
I also think that people who list their cars are also sometimes unreasonable with their demands, no where in the World have I seen the price of a used car higher than the new one, I guess only in Pakistan. I saw someone demanding 11.5 lac for a 2006 manual City when this car was purchased at less than 9 lac FIVE years ago!!!
I think both buyers and sellers share the blame for low balling the demand and also over inflating the demand. If someone install an ad-on, they double the price and add it to the demand.
If you added an accessory, its for your own pleasure, why should I pay for your Paindoo taste.