I know this doesn't help jqworle, but I was talking to my local dealers and he said he has just sold my 2012 K16GT for the fourth time and is just about to get my 2013 K16GT Sport (same model as jqworle's) back in on part-ex. I have no idea what price they pay, but definitely don't turn away business and I know they resell these bikes.
I hate to say this, but buying new is a mugs game, you loose about 50% of the value in three years (both bikes and cars, except Harleys for some reason). And with BMWs you can add all of the tick box options and it doesn't matter much at trade in time. This has only been made worse by the fact that second hand BMWs now have to have two years warranty added to them (along with a full service, MOT, new tyres etc). Not sticking up for them, but it just happens
I get mine on PCP and pay a monthly fee, but each year I look at swapping it in while it still has some worth. I look at the 6,000 mile service, new tyres, a years tax and devaluation. If there is a deal on the ESA or like, I normally end up paying around £2 - £2,500 to upgrade to the newest model. It didn't work so well this year as the K16s had a mid-life face lift and where hard to get, and prices stayed high as well as a price rise and new "extras". I really like this model and will probably keep it, and the PCP buy it now price after three years is £8,900, a big drop from £21,000 new but to look at it another way I will be getting a fantastic, well looked after bike for under £9,000.