Are you saying that there is no B&M store that mark up there stuff? I would email Precision and see if they will pricematch or how close they can pricematch other online stores such as
B&H. Has worked for me in the past.
If you need filters right away you can try craigslist or wolf/ritz, but Precision will have the largest selection in Austin. If you know what you want, you can always post a WTB ad in the Buy and sell section for the austin area. Now if you can wait, you can always buy online and have them expedite an order.