"As Wall Street continued to crunch numbers on what the cost of the spill will be for BP investors, Goldman Sachs analysts took the figures spent by Exxon Corp., now Exxon Mobil (XOM 60.03, -1.21, -1.98%) , in the 1989 Exxon Valdez accident, and adjusted them for inflation to come up with a figure of $40,000 per barrel spilled."
Now the source of the information used was Goldman Sachs... Is that good enough for you??