You should sell the ps3, since you love halo ( Thats y i sold my ps2 and bought an xbox 360)
I find that x-box has much better games on it.
Also, go check out E-bay, or something like that.
I got an x-box 360 and 1 ODST for $150 Second hand.
So yeah, in short:
1. sell ps3
2. Buy x-box second hand
3. PLAY HALO 4!!!!!!!!!!!!!!!!
p.s. Don't sell it to EB games, you'll get like 1/5 of the price of the ps3.
You should sell it on E-bay you'll get what it's worth there.