It could all be very simple.
Start with the actual value of the aircraft, today - where is, as is.
1. If that is zero or a very small figure then they might just give it to you (whether it is already yours then becomes a moot point).
2. If it is a small figure then you might negotiate an even smaller one and decide it's worth paying (or even negotiate down to zero, selling a plane can be hard work).
3. If it is a large figure, then head happily off to eBay/Controller/Planecheck etc. and get yourself whatever you want/can afford.
My 2p.
Sam.