How much would it cost to fix this?

[LegoHead]

And any idea what I should offer? I am after a little project, looks like it could be fixable by buying a few parts without having to replace the whole engine.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=180362901467&_trksid=p2761.l1259

 

[sideways danny]

I'd sling a lump in it TBH, if someone's taken it apart, you dont know what's been broken or lost. trying to find all the bits when you didn't take it apart is the worst job in the world. Unsure on what to pay, not much IMO.