They put them up for sale speculatively, with the attitude of "if I can get X amount I'll sell, otherwise I might as well keep it".That is how it SHOULD work, but things seem to have got a lot more complicated these days.
With everyone (buyers and sellers) having access to multiple sources to 'price' cars....from WBAC and Motorway, Carwow, etc to Autotrader offering 'pricing advice', looking at others for sale on multiple platforms, to 'experts' on car forums and FB it is difficult.
I see many, in fact most, private sellers asking as much if not more than dealers for comparable cars. That is a new phenomenon which I don't like or understand. And what happens to overpriced cars by private sellers that don't sell?
I very rarely see cars keep being reduced until they sell. They seem to just disappear. I can't believe anyone would pay some of the asking prices by deluded private sellers. I have seen some corkers in the past few years and none have been reduced to sell them.
Do they keep them just so they don't sell them for less than they think they are worth? Or do they sell to the trade at less than they think they are worth?
I don't fully agree with your implication that dealer cars should always be valued higher, it depends on the dealer. Main dealer approved used with proper warranty, yes. Pretty much every other dealer, no thanks - I tend to treat them as less well informed private sellers.

