Used aircraft coming onto the market nearly always affect prices of new aircraft and therefore, sales. It's basic market economics. The only way that is minimized is when the demand is overwhelming. The A380 was a game changer - but developed a bit early according to many. There are also those that believe if Airbus can 'hang in there', the aircraft will likely enjoy a minor resurgence down the road.
RE: Concorde - BA, in the latter years of Concorde operations was making a huge profit and she served as a standard bearer/iconic symbol for the airline. For whatever reason, Air France failed to make a profit with their Concordes.
The AF crash was caused by a series of unfortunate events and circumstances. Several BA and early Concorde development folks have been quoted as not blaming the aircraft or (specifically) the strip of metal in various documentaries and books published. Also, to clear up another factual error in this thread: the Continental engineer in Tel Aviv was cleared of all criminal charges. Does anyone else see the bitter irony (considering the history) in the story: a part installed by an American in Israel led to the deaths of a group of German citizens carried by the French?