Actually Open Office gives you pretty much the same for free and can handle all M$ data types (if you want to you can save your documents etc. as .doc , .docx etc. so you stay compatible with the M$ users).
And I wouldn't say that noone knows OO. Quite a lot of us students are using it.
But if you are happy with you M$ Office then there is no real need to change to OO since it is pretty much the same. But if you should ever find yourself in a position that you need a new office software I would give OO a go. If you don't like it you can always delete it and buy the M$ stuff.
