Sorry Alty Meter, your post is absolute rubbish.
Retiring Concorde has resulted in £84 million write-off costs for the year ending March 2003. According to your good self, that would have paid for at least 6 years of continued Concorde operation. I don't think so...............
The figure Airbus wanted was pitched at the level as to make it unachieveable. The French bottled it, Air France is being privatised, Airbus is a French company (no matter what BAE think) and there was no way that Airbus was going to allow BA to become the only supersonic airline in the world. After all, in 5 years the economy would have picked up and BA holding out would have been seen as a prudent decision whilst making Air France look extremely stupid.
What you are essentially arguing is that BA spent more money on cancelling her than would have taken to keep her alive. Not a tenable position methinks!