I did the same in '03. BA released some steeply discounted tickets with the end-of-life announcement; I think I paid $3,500 round trip (JFK-LHR leg in coach, my rationale being I could afford one way and London to New York was an hour more time on Concorde).

It was also noisy and cramped. Fantastic though, it was a once-in-a-lifetime experience and a wonderful thing to have done.