I believe he is talking about something like a K&N drop in filter, which although it will increase performance, you shouldn't expect anything more than 1-2HP.

A Short Ram intake will give you quicker throttle response, and free up even more HP, but the best choice would be a 2 Piece Cold Air Intake which would place the filter away from the engine bay, allowing the engine to breath cooler air rather than air heated by the engine.

If you want to save money, then I suggest doing it right the first time and getting a Cold Air Intake. I believe that you will get the best results and be very happy with an actual CAI versus a short ram or drop in filter.

~Peace