Should I get xbox live?

Ok I freaking love call of duty I could sit and play for hours I don't have live but I played at my friends house and I was having soooooo much fun playing zombies she wanted to quit and I got so sad hut did anyway right now I have a headset high speed Internet but I need a adapter and the membership so it's gonna be about 100 dollars I also have sims 3 and I only get half the gaming experience because I don't have live I have about 20 games and play at least half the day every day so should I get it cuz that's alott of money if I'm gonna get bored in like a week please no rude answers and thanks in advance