Yesterday I went to buy new sneakers and as always, I chose Adidas for the brand. It is my favorite brand for sneakers, not really sure why. I just think they have best classic designs.
Adidas is available almost everywhere in Taiwan and you can expect to spend anywhere between NT1200 to NT3000 for a pair of sneakers. Sometimes they have additional promotions, which are also nice.
You can apply for their VIP status (15% off) if you spend one time over NT10000.
I recommend you to buy your sneakers at their store, and not in the night market. I remember I bought some Adidas some time ago in Shilin Night Market - although I paid about 1/3 cheaper than Adidas store, somehow I think the quality is not that good (fakes?) which only lasted for 2-3 months.
In the official stores, you can also buy sport clothing, bags, and gym necessities. I haven't really had a chance to take a good look at the prices, but from my memory:
1. Sneakers: NT1200-NT3000
2. Soccer Jersey: I noticed AC Milan and Liverpool jerseys for NT2250.
3. T-shirts and shirts, work out shirts for about NT500-NT900