When you are selling a car it is easy to feel like the car will never sell and that you are getting rejected from every which way. If someone rejects your proposal it is worth offering them a compromise. If someone is after a specific model (i.e. the one you are selling) then this works best. Tell them that you willing to match the price on the same model if they find it elsewhere. At this stage it is probably the best you are going to do anyway.
Selling a car can be the result of compromise. A compromise such as this can ensure you make a sale and will work to give the buyer the best deal they can get.
If the buyer comes back with the price it is normally nice to have a way of verifying that they arent lying. Ask them where they got such a great price and if you cant (or dont want to) match it give them a figure between your asking price and the price they want it for. At this point the buyer has probably done a lot of travelling in order to get the best price they can and will want to just close the sale. Selling a car does require a few little tricks sometimes; this is just one way that can ensure your buyer buys from you and not somebody else. If you feel like this is unfair or not legitimate then dont; car salesmen have using this trick (and worse) since used cars have been a commodity.
Dont be afraid to test the waters a little when selling a car. If you believe in your car then you shouldnt be afraid to do what it takes to sell it. You are probably going to be offering the vehicle at a drastically reduced price compared to your asking price so either way, there is no real reason to feel ashamed. If you have saved your buyer money while remaining happy with the price you have got then you will have concluded a successful sale while selling a car. It is a dog eat dog world, it is better that you get the sale than someone else. Just because you are selling a car does not mean you have to rely on the buyer entirely.