There were 91 days in Apple's fourth quarter with quarterly revenue of $90.1B. At 7862400 seconds, that means $11,446 of revenue every second. 98000000/11446/60 = 142 minutes of revenue.
They should just dump the tax-free shopping stuff, or go to the way other countries do it where you send some forms in and get sent a refund, rather than having individual stores process the paperwork, usually with special counters for tax-free shoppers.