Of course E-Bay and Amazon are the best places to buy at a discount. But if you want to buy from a store, try www.runnersworld.com. They have good prices and a good reputation.
You can get running clothes at many places. Some places where you can look is www.roadrunnersports.com or www.athleta.com/products/running-clothes.jsp.
Since running clothes still fall into the category of "clothes" it is likely that you'd be able to buy some at a department/clothing store. Athletic stores (i.e Sports Authority) would probably be a good place to look as well.
If you want to buy running clothes from Adidas, it is possible because they sell outdoor running wear, shoes, and more.
Yes, you can buy cute running clothes online. For a female I would recommend, Forever21 or Victoria Secret, they carry a cute line of adequate and low price running clothing. For men, I would recommend Columbia.
Runnersworld.com offers some very cheap running clothes online. They offer a variety of clothes from head to toe all for under 100 dollars as experimented by their editors.
At the clothes stores, or on the street markets.
lol you have to show us your clothes
The best place to go is online at www.roadrunnersports.com/ They have all kinds of clothes and accessories for the everyday runner. The sell men's running shirts at good rates.
You can buy running clothes online from Roadrunnersports.com. You can also find this type of apparel at REI.
Exercise RIGHT, eat healthy, buy good clothes!
Yes, the national running center is a great place to buy fitness items. They have everything you need including clothes, shoes, hats, etc. Whatever you need to stay fit, it is there.