adidas via eBay takes an extra 25% off a selection of its adidas men's, women's, and kids' styles. (Discount applies in cart.) Plus, these orders receive free shipping. Deal ends November 12. A couple of best bets:
adidas Men's Cloudfoam Racer TR Shoes for $29.99 (pictured, low by $17)
adidas Women's Flashback Shoes for $37.49 (low by $43)
Credit cards offer many conveniences and protections, but sometimes it's simply smarter to keep the plastic tucked away.