Quite true...
However, there is a big difference to pay a professional to install and configure a Microsoft system where everything is designed to work together -- and having to pay to have someone cobble a bunch of disparate and incompatible applications together into what 'appears' as a single unified system.
I've built very complex systems of up to 20 servers and half a dozen MS applications in a couple of days (including hardening, SPs, cumulative fixes and updates).
I've watched a lot of F/OSS folks try the same in much simpler environments and have seen them take many weeks to achieve a similar result.
One can buy a lot of licenses for that kind of money.
