With the prohibitive costs of rolling out to a new operating system and Microsoft's draconian stipulations on licensing of old software, it's no surprise at all that some companies, and in fact, some Governments, are purchase used licenses for older vesions of Windows. Munich, in Germany, is purchasing 2000 copies of Windows 2000, and saving quite a bit of money in doing so. While the software itself hasn't changed a bit, the value goes down considerably, especially now that Vista is here:

That's not surprising: for instance, 218 licenses of Windows Office XP will cost 70,000 (47,000) in Germany, but when used, the price drops to 32,000. 400 licenses of mySAP Business Suite will set you back at 1.5 million, but 400 second hand licenses will sell for 750.000.

For companies that don't rely on Microsoft as a support company and don't require the added functionality Vista brings, it's entirely logical for them to purchase older software. Interesting stuff.