Should I get a Xbox 360?

I was thinking about getting a Xbox 360 but my stepdad has one and he has all the games because he burns them off the internet so he has them before they even come out and he modifies them so you can play games off the internet but anyway he has all the games , xbox live , the headset and the guitar for guitat hero (which im real good at ) and all that and lately I've been playing nba2k on his and last night I got on xbox live and talked on the headset with someone for the first time and I loved it and thought it was real coo so I kinda want my own so I can play it in my room whenever I want instead of in the living room and if I go somewhere I can bring it because it would be mine but some of my friends are saying no because I can just use his whenever he's not playing and it would be a waste of money being that we are in the same house , but some of my friends are saying yeah I should buy one so I don't end up breaking his or something and I can play it whenever..what do you think???