I didn't but get mine online though there are companies selling used tires online. You'll still have to pay for shipping. There is Used Tires for Sale at Discount Prices - BestUsedTires.com which looks pretty good. I bought mine locally using the method below.

Look on Craigslist in the largest city near where you live, they have a category in auto parts just for wheels and tires. I live in SE Michigan so I found mine near Detroit which may be better than other locations. The best part about buying used is that the dealer checks the tires, you can look at them also, and you can buy what you want rather than what a tire store (new) wants to sell you. You may find tires from a private party also, I've done that in the past.