I agree. A car that sort of age in that price bracket needs to be much more cheaper than dealers. People who can afford that sort of money for a horrific looking supermini can afford to pay the extra couple of grand to buy from a proper dealer.
You need to advertise to your market too, people who buy this car will be 40 something women I reckon..... probably not many of those browse on, or have even heard of pistonheads. Get it in the autotrader, on the sales board in sainsburys, park it outside posh schools with a for sale sign in the window at 3.30 pm etc