If you have been waiting to buy Halo 4- this is YOUR deal.
Right now on Amazon you can get Halo 4 for $39.99 on Amazon. PLUS when you buy it you get a $10 Amazon Instant Video credit. Your Amazon Instant Video credit will be automatically applied to your account when your order has shipped. Offer valid when shipped and sold by Amazon.com. Limit one per household. This offer extended to pre-orders.
So you can save the $10 credit and use it for something else!
Remember Amazon can change the prices any time they want so be sure to double check before you buy!