Amazon has Adidas Men's Techfit Short-Sleeve & Long Sleeved Fitted Shirts from $7.48+. Free Shipping with Amazon Prime (free prime one month trial or Free student accounts, and Amazon Mom accounts) or with $25 or more purchase.
To find the lower priced shirts you will just have to enter your size and check all the colors. Each color is a different price, some are on sale and some aren't: