Some think that it's highway robbery that the 30-pin to Lightning converter costs $30 retail at the Apple Store. Well it's not just a pass through connector, it's actually much more.
The Lightning converter is actually an digital to analog converter. The new Lightning connector is all digital. Meaning that everything transferred to and from it needs to be digital. So if you want to connect your iPhone 5 up to your analog car stereo, you'll need to convert that sound from digital to analog. That's what the Lightning converter is and why it costs $30.
The real issue is that more people need these just for charging -- and for that, you are better off getting a $19 Lightning to USB cable instead.