The ones to "trick" the ECU are not worth anything unless you have a pre-1998 Ranger generally. They just modify a sensor input and later Rangers aren't fooled by that enough to matter.
A "real" chip costs hundreds of dollars, as do "tunes" with programmers, and they are worth it. That's a new program that actually changes how your ECU operates.
Cold air induction (ram air I'm talking here) only makes a difference at very high speeds. With our small engines the HP gains are anemic -- but they are real and I guess everything counts.