What kind of discount should you get from a dealer

Hi, We have ordered a new motorhome quite a few months ago with lots of extras (£55.000 with extras) and a part exchange on our old motorhome. We did not get a discount as such but £1950 of free extras that we requested and £2000 extra on top book price of our old motorhome. Can anyone tell us is this a good deal (tryed hard too get the deal we got but have not completed it yet!, not good at this kind of thing)  or should we expect better ?? What percentage should you try and get from a dealer and what are your experiances ??