Slashdot | Calculating the True Worth of Software:

"Many people recognize that the cost to duplicate a piece of software is a fraction of the number on its price tag. Many people also understand that software without support and maintenance loses much of its value. Is there a way to put a price on the software, support, maintenance, and the option for future upgrades itself? Robert Lefkowitz recently applied an options pricing model to software in ONLamp.com's Calculating the True Price of Software. Don't let the description fool you; it's both a readable and serious apologia of the common free software business model."