To be brutally honest, if it is your money then you should spend it according to your needs. I had that same issue with me mum when I was living with her. She was always like, "All you do with your money is buy Pac-Man (video games)!" which was BS. She would always run away with 75% to 112% of my paycheck for groceries and things which I had no problem with, but it hurt that she would criticize me and yet depend on me. WTF? So, I got my games via trading or stealing ( :icon_bigg )as I couldn't buy them. But if you're not in the situation I was in, then spend your money as how you want to. Hell, if I were you I would buy bullsh*t like pr0n and cigarettes and go into their room and be all like, "Look, imma fap to lesbians while smoking!!!! Haha! Capitalism!" But leave out the smoking bit. It's not good for you.:)
Edit: I forgot to mention my point(I'm a really good spammer, I know!). Buy a PC if you need a new one. If you think you could survive with just Linux on a PS3, make sure you at least have an HDTV so you can view everything on screen.