Just in time for back to school shopping, this Texas Instruments TI-84 Plus Calculator drops from $114.88 to only $88 at Walmart. You save 23% off the retail price for this graphing calculator. Plus, this item ships free. This is the lowest price online by about $12. The TI-84 Plus Calculator features 12 preloaded apps, USB cord, and the graphing calculator handles calculus, engineering, trigonometric and financial functions. Sales tax is charged in most states.