OK, I apologise, didn’t realise the £3k is what they are NOW saying the difference is.
What I’m trying to say, and obviously not getting over well, is that when I’ve gone in to look at cars and PX mine, I’d already have a reasonable idea of what that PX would be (Parkers, Autotrader, etc.) and also what sort of dealer discount you’d get on the new one. And I’d expect to be lowballed to start with and have to work to what I thought it would be. I agree, that they can fiddle the PX and the dealer discounts so it isn’t always obvious whether what they’re offering is right, but in the end I know roughly what the cost to change is likely to be.
I misunderstood where the £3K number came from, but if after doing that their offer was £3K different to what I’d expected, as I say I’d be suspicious. And perhaps I am too honest but I’d be tempted to query that, even though it would cost me. Too honest or just plain stupid, YMMV
I’d also say that if trading in a prestige/pristine E-class (what would that be, 15-20K?) and being offered only £200 less than I’d been offered on a private sale, that too would have raised an eyebrow.