1000 credits for Halo 4? Um. No thank you >.> I've sold games released in 2009 for around 7 to 8 thousand points. I don't think it's sensible to sell a game released recently for 8 times less than that.
Like I said, I've sold old games for, actually, up to 11,000 points. I'm going to let it ride out until it ends, or someone offers me a more suitable price.