It's tricky, not many people in the UK could actually house one, so resale value might not be as high as it should be. For myself I wouldn't sell mine for any price but that's just me I'd say you should expect to get at least 2 - 2.5k if you were to sell one in the UK in good condition and working/complete. Double that if it were absolutley mint. This is only my opinion though.
They are very rare, there are 5 known ones in the UK. They do come up from time to time in the US but they tend to get snapped up quickly.
That one looks like it's missing the back glass (which is made of unobtanium), and the foot cover bezel. On the plus side it looks like it has a repro CPO and foot graphic, and it looks mostly working. Bear in mind you'll need to use a monster stepdown transformer to run it on UK power.
It appears to be missing the rear glass artwork, and various parts that would light it up. I think some wood work is also missing at the bottom and various fixing brackets.
Well if someone on here sells me one... then I wouldn't have to consider it. It looks amazing complete. Maybe save up for the better complete one, and might get it cheaper. I need a TRON machine first before I consider a disc of tron.