The TRD one is right around $300 & I've read the most positive comments about that one as it has a lower inlet that attaches to the bottom side vent near the wheel. Of course, it's also been out longer than the AEM. I don't know the price of the AEM CAI yet... anyone?
Or, you could always build one yourself using a material besides metal for less heat soak.
Or, you could always build one yourself using a material besides metal for less heat soak.