Clearly the dealer thinks he can get the full £10k for it. You could try waiting a couple of weeks: if it hasn't sold he may be more amenable to an offer. Or look on Cars for Sale on this site as well as Autotrader: there should be plenty of Octavias around.

Here's an idea you might have played with or could use in the future.

You've moved forward on this by now I hope- but one approach I've heard about, would have been to ask the salesman what the £10k includes. The objective being to encourage him/her to once again articulate the benefits, the bells and whistles, " 6 months tax", "guarantee", new MOT with no advisables?, full service? etc

Once he/she has finished this spiel-you should pause and look as though you are doing some thinking. Don't speak other than say " Yeah--ok- certainly worth thinking about that"...the fact that you haven't said yes or no-might encourage salesman to then ask you to come up with an offer. Then--what you could say is "it's a little higher that my notional £8.5k limit--which i could offer right away-cash"....quite rightly the salesperson might then be thinking that they have a reasonably serious buyer , so might throw in a further gooodie or two( car mats, full tank of petrol etc). Don't commit-You should still look and behave siliently. After a pause- If you feel bold--why not ask salesperson to go and speak to his manager. If you don't--ask for time to think, exchange telephone numbers and say you'll get back to them . I guarantee the dealership will ring you within 24 hours

Dealers don't like stock sitting on a forecourt taking up space. Yes --your offer of £8.5k is probably a wee bit too low--but as a way forward-manager might-just might- knock £500 off the £10k. If not--then walk away.