Yea, TF2 is a game provided by Steam. It is normally available for $19.99 at http://store.steampowered.com/app/440/. but, if you are not in a rush to get it, you can be on the look out for one of Steam's sales, where everything is half price. I bought it during the Christmas *ahem* holiday *ahem*(politically correct) sale for 10 bucks.
Thay have HALFLIFE to