David's Elise S will be slightly harder to shift through dealers, but if you are keen just to clear the finance, then maybe the figure a dealer is likely to offer will be in that region.
I think given your mileage, it is black and has a stage 2 will hopefully prove a reasonably attractive buy on the likes of Pistonheads.
Just my 2p, but I think you can walk out of this without feeling like you have been stung by dealers, and with a little effort, you could walk away with a bit more cash for your new..........?!!

You take the pictures sir, i'll sell them both for you! Among many ideas i have on the go just now, as an aside to the contract hire business, i am keen to provide a specialist car buying and selling service, as i just can't get away from my time in the motor trade! Have sold and bought 5 or 6 cars this year so far for others!
Cheers,
Dave