Walmart offers the Tone Fitness Anti-Burst Stability Ball in Pink, model no. HHE-TN055, or Blue, model no. HHE-TN065, for $5. Choose in-store pickup to avoid the $5.97 shipping fee. That's tied with our mention from last week and the lowest price now by $2. It's designed for core and flexibility exercises. (Note that the pink ball is 55cm, while the blue is 65cm.)