I found that Auto Parts at AutohausAZ - OEM Auto Parts - Discount Replacement Parts, Resources and Car Care Tips and RockAuto Auto Parts have competitive pricing but you will be charged shipping. Recently I have been looking at both the air and cabin filters and those two places seemed to have pretty good internet pricing. I then started comparing the internet prices to our local (nationwide) parts stores (Auto Zone, O'Reilly, etc.) and found that while the part stores were a tad more expensive per part, you didn't have to pay shipping, so it was worth buying locally.

Just my $.02

RL