The 'spread' on Aeros between what a dealer offers and what he asks is very large - at least £10K from what I've seen so there should always be a good reason to buy privately if possible. But I expect that almost every Aero needs a bit of fettling or paint or whatever, and then there's the warranty too.
Quite a few dealers offer to sell 'on behalf of the owner' so only pay on sale, and then obviously take a lower margin. But it's still quite a lot.
Mind you, after experiences I've heard with Aston Martins this is hardly unusual in the semi-exotic part of the car market, and there's always the need to pay salesman's salaries, advertising, and premises, so perhaps we should expect nothing different.
It certainly stops me from thinking about changing my S3 to an S4, or a Supersports or whatever. Perhaps Charles should consider a special trade-in scheme for Aero derivative owners to make trading-up a more easily palatable exercise? I know he's keen to promote trade-ins and customers switching cars more frequently than is the Morgan tradition.