Well, a kidney could be worth about £20,000 if you had the tissue type and medical history of the 'donor' in advance. I know that organ theft has been done in India, but I'm not sure that it was done on the 'gentlemanly' basis of performing a semi-sterile procedure under sedation.
Now wasn't there a Robin Cook novel about somebody who was on the waiting list for a new heart or liver? If I remember correctly, the guy found out who was on the organ donor list, got their tissue types off the hospital computers and then 'helped' people of the same tissue type to have accidents that would ultimately make them suitable for organ harvesting...
I suppose it's not a big stretch for something like that to happen in reality :-o