Cars are one thing, but definitely don't buy a used toilet seat that's been in an accident, definitely not from William the Third.
I would tend to agree with RuleOfSines, but also know the feeling of hoping to get a great deal, especially if there wasn't much actual damage. If you want to pursue it further - do you have any friends in collision repair? Someone who knows what to look for might be able to at least give you an idea of what damage may be hiding beneath the bumper. My brother does body work, and I've asked him stuff like that - he can usually pop a few clips in a matter of minutes and take a look at the pinch welds for cracks and deformation.