I dont get it, air is air right?

[KONG]

I know the difference in quality between air filters but what is the difference between an expensive (2-3 hundred dollars) air intake and those intake systems you find on ebay for about 60 dollars shipped? I bought a no name brand from ebay for my dodge ram and it worked well. But I never have tried the expensive way to notice the difference. You would think that better air flow would increase HP but why the big difference in price just to have the name.

Who has the ebay 60 dollar air intake system and who has the 300 dollar system? Can you justify the cost when you can get basically the same set up for about third of cost?

Please help the confused to make a decision