for sure it's free..
Sose, admit it, what do you have against Linux? :wink:
Not only it's free, also most programs are running on it are open source and free, you can make a business just by running a Linux server and having Apache, MySQl and PHP on it for web hosting services, also you can use it in ISP environment, there are free radius server when you can do all accounting and billing maths and all for free or for a very low cost..
I think in any field, it is better to have competitions.. if there is no Linux, then may be Microsoft will not work on making their products better and cheaper..
always Face your Fears...