Welcome to Ribnet!
There are 2 ways of looking at that ebay sale:
- if they can't be biothered pumping the toobs up for a photo, how well looked after has it been generally?
- you could get a reasonable bargain, as the engine isn't attatched, so a lot of people might get put off.
I guess it boils down to how confident you are with rigging the engine and confident about repaiing things that may go wrong. Patching the odd puncture is no worse than a bike tyre repair on a bigger scale. Your definition of "repairable engine" Is down to you. Also check he has removed the throttle lever from the remotes as well, otherwise you'll need a new one of them for starters!
If it was me, I'd be giving it serious thought, but I should warn you I have an annoying (for my wife!) habit of buying cheeeep boats & resucuitating them, so I probably have a slight bias towards the "requires TLC" end of the market!