Turbo charger bodies will impart heat into the inducted air so within reason it's academic. You need to be more concerned with the temperature of the air when it leaves the intercooler as after this it arrives at the cylinders where it's used for combustion and this is where temperature and density of inducted air really matters. For an NA car it's a different story. CAI's matter and work here.
Your intake plumbing will get nowhere near as hot as a turbo charger body and consider that the very act of compressing air will heat it.
There is science in the flow dynamics of the formed tubing of both the Revo and Evoms for instance and you're paying for development costs and some tooling costs. It's also a matter of asking what people are prepared to pay. There is scientific fact in the development of these products and there is also a good degree of marketing. This is after all how businesses make money.
A heat soaked intercooler is your worst enemy.
BTW - a standard intake will meet the technical demand for flow volume at stage 1, but maybe not the aural specification you have in mind!
