Bro,
What do you want to achieve with your sound proofing? Reduce spillage or just reduce the reflections in your room?
There's not way to totally soundproof your room unless you reconstruct another room within your room, that essentially decouples the new room from the floor thus preventing sound from travelling out of the room. That way, if you want to blast your Marshall amp at 3am in the morning, your neighbours won't hear a single thing.
If you just want to reduce reflections, then I suggest identifying problematic areas in your room and treat it accordingly. Check with Luthermusic, they do bring in some quality acoustic foam.
There are 3 kinds of sound treatments that people go for, 1) Acoustic Isolation, 2)Controlling propagation of sound waves and 3)Reducing reflections and standing waves.
You gotta ask yourself what you want to achieve before forking out money to buy stuff that will not suit your needs and in turn wasting money. I've been there. Done that, I know how it feels. =)
