What's The Actual Cost of A Virus?

ThosLives writes "CNN Money just posted a story that says the MyDoom virus may cost businesses $250M. My favorite quote is that for small to medium businesses with 400 or less employees, the estimate is between $48,000 and $58,000 cost to 'secure themselves' from the particular virus. Does anyone know where that number comes from? If one can charge a year's salary to fix one virus, I'm in the wrong job! Any input out there on the real, hard costs of things such as virus protection?"