ebay. You can new, in box items that still have warranty. I bought an Altec Lansing portable stereo for my ipod for $150 then saw a variation new in box on ebay for $70. Live and learn.
It was the cheapest iTrip price I could find at the time and they were one of the few places that offered the case I wanted. I didn't have any problems with the company as far as payment or shipping goes.