As a rule, anything that cannot be lifted - i.e. curtain poles, is classed as fixtures and fittings.
As far as the other items are concerned, if you need them you will be able to buy 9and choose) your own for far less than is being asked here.
I would be inclined to call their bluff, and advise them that you don't require any of the items, and look forward to the house being left completely without any of the items listed.
You may find that when they realise they have the fag of removing and selling on the items, which they will do if they are emigrating, then they will drop the price.
If not - you have nothing to lose, let them take their inflated price items away, and you can replace them for far less than they are asking.