Updated. Originally $99, Gaiam's Ergonomic Balance Ball Chair is on sale for $79.98. Enter code AFSAVES6 through 6/30 and cut that to $63.98, the lowest price around. The chair includes a removable 52cm Balance Ball, an adjustable support bar, easy-glide casters, an air pump, and a desktop guide to get you moving. It's designed to strengthen core muscles and improving spinal alignment as you go about your daily office routine. Shipping adds $9.99. There is no sales tax (except CA, CO, OH).